Production of an ultrasound sensor

Abstract

The invention relates to a method for producing an ultrasound sensor, the method comprising: assembling a transducer unit of the ultrasound sensor, wherein the transducer unit comprises an electroacoustic sound transducer and a soft component, wherein the soft component comprises a curable material; applying an energy supply dimensioned for curing the curable material to the transducer unit; and configuring the ultrasound sensor to carry out a self-calibration in order to compensate for ageing of the sound transducer.

Description

MAKING AN ULTRASOUND SENSOR AREA OF TECHNOLOGY

[0001] The invention relates to a method for manufacturing an ultrasonic sensor as well as a corresponding computer program product and computer system. STATE OF THE ART

[0002] Ultrasonic sensors can be configured to transmit and / or receive ultrasonic waves. Because of this capability, ultrasonic sensors are used, among other things, in the automotive industry to determine the distance to an obstacle reflecting the ultrasonic pulse based on its travel time.

[0003] Ultrasonic sensors for distance measurement using the pulse-echo method can operate on the principle of a bending transducer in resonance mode. A piezoelectrically active element, bonded to a rigid diaphragm, can be used for electromechanical energy conversion. If the same diaphragm and sensor element are used as both transmitter and receiver, high damping of the oscillating system may be desirable. This can be achieved, for example, by applying a damping material, such as a foam with high inherent damping, to the diaphragm.

[0004] The performance characteristics of an ultrasonic sensor can change due to the aging of its components. This can particularly affect adhesives, foams, the polarization of the piezoelectric element, and electrical components. Aging effects can manifest themselves through altered... The resonance characteristic / transfer function can be made noticeable, e.g., by a changed echo amplitude with an unchanged stimulus and echo environment.

[0005] Ultrasonic detection systems in automotive engineering can utilize multiple ultrasonic sensors in a sensor network. Such networked sensors can function as both transmitters of pulses and receivers of echoes. The individual sensors can interact by receiving not only echoes of their own transmitted pulses but also echoes of pulses from other sensors. For accurate evaluation of the coupled signals, it is advantageous for the sensors to have uniform characteristics and to age uniformly or not at all. However, aging behavior can vary depending on the sensor and / or the application (e.g., due to different temperatures at different locations). Aging can also be a function of a sensor's service life, for example, with a high aging rate for a new sensor. Sensor performance gradually deteriorates with age. For example, when replacing individual sensors in a sensor network, different characteristics can be active simultaneously, reducing the integrity of the measurement data and its evaluation.

[0006] To minimize the impact of aging on the transfer function of the transducer unit, and thus on the output signal of the ultrasonic sensor, while simultaneously ensuring a uniform characteristic across different sensors, ultrasonic sensor assemblies can undergo a pre-aging routine. This involves subjecting the assembly to a high energy input (e.g., thermal, acoustic, electromagnetic, chemical) during manufacturing, which accelerates the aging processes of the assembly's components. For example, a sensor can be thermally pre-aged by subjecting it to several multi-hour heating and cooling cycles, which include heating the assembly to typical temperatures above 100 °C and subsequently cooling the assembly to typical temperatures below 0 °C.

[0007] It is an object of the invention to provide an improved method for manufacturing an ultrasonic sensor as well as a corresponding computer program product and To provide a computer system. The problems underlying the invention are solved by the features of the independent claims. SUMMARY

[0008] In one aspect, a method for manufacturing an ultrasonic sensor is disclosed, wherein the method comprises: Assembling a transducer unit of the ultrasonic sensor, wherein the transducer unit comprises an electroacoustic transducer and a soft component, the soft component comprising a curable material; Applying an energy input to the converter unit, measured to cure the curable material; and Configuring the ultrasonic sensor to perform a self-calibration to compensate for aging of the transducer unit.

[0009] In another aspect, a computer program product, in particular a computer-readable storage medium that stores computer-executable code, is disclosed, wherein the code is executable by at least one processor of a computer device to cause the computer device to control a plant for manufacturing ultrasonic sensors in order to execute a method for manufacturing an ultrasonic sensor, wherein the method comprises: Assembling a transducer unit of the ultrasonic sensor, wherein the transducer unit comprises an electroacoustic transducer and a soft component, the soft component comprising a curable material; Applying an energy input to the converter unit, measured to cure the curable material; and Configuring the ultrasonic sensor to perform a self-calibration to compensate for aging of the transducer unit.

[0010] In another aspect, a computer system is disclosed, comprising a processor and a memory functionally connected to the processor, wherein the memory stores computer-executable code, wherein the code, when executed by the processor causes the computer system to control a plant for manufacturing ultrasonic sensors in order to execute a method for manufacturing an ultrasonic sensor, wherein the method comprises: Assembling a transducer unit of the ultrasonic sensor, wherein the transducer unit comprises an electroacoustic transducer and a soft component, the soft component comprising a curable material; Applying an energy input to the converter unit, measured to cure the curable material; and Configuring the ultrasonic sensor to perform a self-calibration to compensate for aging of the transducer unit.

[0011] It is understood that one or more of the embodiments disclosed herein may be combined with one another, as long as the embodiments do not exclude each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The following examples are explained in more detail using the drawings. They show: Fig. 1 shows a block diagram of an ultrasonic sensor, and Fig. 2 shows a block diagram of a plant for manufacturing an ultrasonic sensor. DETAILED DESCRIPTION

[0013] Ultrasonic sensors (hereinafter also referred to as "sensors" or "sensor") can have a vibrating element, such as a membrane, which is designed to decouple an ultrasonic wave generated by an exciter, such as a piezoelectric element, as an ultrasonic body wave into the air surrounding the sensor and / or to vibrate in sync with an ultrasonic body wave arriving from the air surrounding the sensor. For the sake of simplicity, the vibrating element will be referred to as the "membrane" in the following. The entirety of the structural elements directly involved in the conversion between acoustic and electrical energy, i.e., the membrane together with the exciter, will be referred to here as the "sound transducer".

[0014] The transducer can be acoustically coupled to other elements and / or structures of the ultrasonic sensor, whose mechanical properties influence the vibration behavior of the diaphragm or transducer, in particular the response of the diaphragm or transducer to an ultrasonic wave coupled into the diaphragm. The transducer, as well as those elements and / or structures exhibiting a mechanical property whose typical change behavior over the lifetime of the ultrasonic sensor leads to a significant, measurable change in the vibration behavior of the diaphragm, are collectively referred to herein as the transducer unit of the ultrasonic sensor. Measurable changes in the mechanical-acoustic properties of the transducer or of elements, structures and / or materials acoustically coupled to the transducer could cause a deviation of an output signal emitted by the ultrasonic sensor at a time during operation during the sensor's lifetime after manufacture compared to an output signal generated under identical conditions in a brand-new state.

[0015] To maintain consistent functionality of the ultrasonic sensor, it is important to suppress changes in the vibration behavior of the diaphragm or transducer due to aging and / or said age-related changes in the mechanical properties of the acoustically coupled elements and / or structures of the transducer unit as much as possible, or to know them so well that the influence of such changes on measurement data encoded by an output signal of the ultrasonic sensor at any given time within the sensor's lifetime can be calculated out.

[0016] The method disclosed herein for manufacturing an ultrasonic sensor includes assembling the transducer unit of the ultrasonic sensor. Without limitation, components of the transducer unit may include a body, a diaphragm or other vibrating element, an exciter such as a piezoelectric element, a damping element such as a piece of polymer foam, mechanical connecting elements and / or materials such as adhesives and / or screws, and / or other structural elements.

[0017] It is understood that the transducer unit does not necessarily have to be manufactured as a discrete assembly; however, the components of the transducer unit can be elements of a larger assembly. In this case, unless otherwise specified, features, process steps, etc., relating to the transducer unit are to be understood as relating to the entire assembly, so that the transducer unit, as part of the assembly, is included in the features, process steps, etc. The assembly containing the transducer unit could comprise the fully manufactured ultrasonic sensor or only a part thereof. In particular, for example, the application of the transducer unit (or...) could...the assembly comprising the converter unit) with an energy input dimensioned for curing the curable material (hereinafter also referred to as "the application") or on another process step disclosed herein, further manufacturing steps may follow, which may extend to the completion of the manufacture of the sensor.

[0018] The transducer unit comprises the electroacoustic transducer and a soft component acoustically coupled to the transducer, which consists of a curable material. A soft component could, for example, be a damping element connected to the diaphragm, or an adhesive incorporated into the transducer unit or the assembly containing the transducer unit. Without limiting generality, the curable material could be a polymer.

[0019] The curable material could have a soft, liquid, or semi-liquid consistency during or immediately after assembly and / or be plastically deformable. This mechanical instability of the soft component could be desirable during the assembly of the converter unit; for the complete However, for a manufactured, ready-to-use ultrasonic sensor, a higher level of mechanical stability might be desirable, avoiding a rigid or purely elastically deformable state. Soft component required.

[0020] The process further includes a step of applying an energy input to the transducer unit, dimensioned to cure the curable material. This could cause the curable material to cure. Without limiting generality, the energy input could be provided by transferring heat, sound waves, electromagnetic waves, and / or other forms of energy to the transducer unit or an assembly containing the transducer unit.

[0021] Typically, in addition to the soft component, other components of the converter unit or an assembly containing the converter unit could represent additional energy sinks for the energy input. This could be compensated for by taking the additional energy absorption of the other components into account when dimensioning the energy input. With the larger energy input dimensioned in this way, it could therefore be ensured that the curable material of the soft component cures.

[0022] When determining the energy input for curing the curable material, it is important to consider that this could define a criterion that limits the choice of the amount of energy transferred with the energy input. On the one hand, an insufficient amount of energy could result in the curable material not curing completely. In this case, the energy input would be too low to be sufficient for curing the material. On the other hand, an excessive energy input could provide an energy surplus that exceeds what is necessary for complete curing. Such an energy surplus might also no longer be sufficient for curing the material if it has a significant, measurable effect on components of the converter unit that goes beyond the curing of the material itself.Possible effects of a significant energy surplus could include accelerated aging of components. include a transducer unit, which could be demonstrated, for example, by a change in the vibration behavior of the sound transducer compared to its vibration behavior when the energy input is dimensioned with an amount of energy that is just sufficient for the curing of the curable material.

[0023] The method further includes a step of configuring the ultrasonic sensor to perform self-calibration to compensate for transducer aging. For this purpose, the sensor could be equipped with an electronic circuit incorporating logic that implements a self-calibration routine. For example, the electronic circuit could include one or more integrated circuits providing one or more processors and memory, with the processor configured to execute program instructions stored in memory that implement said self-calibration routine.

[0024] The self-calibration routine could be based on a calibration measurement. For this purpose, the ultrasonic sensor could switch to a diagnostic mode in which the calibration measurement is performed. In a non-limiting embodiment, the calibration measurement comprises exciting the diaphragm with a predetermined excitation signal and measuring a quantity that represents the diaphragm's response to the excitation signal. In a specific, non-limiting example, the excitation signal could operate the diaphragm exciter with a predetermined current, and the diaphragm's response could be recorded by measuring the time course of an electrical test voltage applied to the diaphragm. From such a time series, further diagnostic information, such as an integral function, a gradient function, a mean value, a maximum, a minimum, and / or other quantities and / or values, could be derived.

[0025] In addition to programming and / or otherwise configuring the ultrasonic sensor to perform the self-calibration routine, configuring the sensor to perform self-calibration could include performing the calibration measurement for the first time. The result of the initial Calibration measurements (measurement data and / or derived information) could be stored in the sensor's memory as a reference dataset, documenting the transducer unit's condition at the time of manufacture. A subsequent call to the self-calibration routine could trigger a re-execution of the calibration measurement, returning a current dataset. The self-calibration routine could then compare this current dataset with the stored reference dataset and convert a sensor output signal based on the comparison result. In this way, the converted output signal could simulate a factory-new ultrasonic sensor without any age-related performance degradation.

[0026] In summary, the method could combine the feature of an energy input precisely measured for curing the curable material with a self-calibrating sensor configuration that computationally compensates for the effects of aging processes in the transducer unit components on the sensor's output signal. This could have the advantage of eliminating the need for pre-aging the transducer unit, as is known from the prior art for minimizing subsequent aging effects after manufacturing and for standardizing the output signals of different sensors.In particular, this could result in considerable time and energy savings in the manufacturing process of an ultrasonic sensor, as multi-hour pre-aging cycles (for example, repeatedly heating sensor assemblies to over 100 °C and cooling them to below 0 °C for thermal pre-aging, which can take 10 hours or more) could be eliminated. Curing without pre-aging, on the other hand, could be significantly shorter, for example, 1-2 hours. Furthermore, this could simplify the design of a production line for manufacturing ultrasonic sensors, as the removal of ultrasonic sensors from the line for pre-aging, the equipment required for pre-aging the sensors, and the subsequent reintegration of the pre-aged sensors into the line would all be eliminated. In one example, the ultrasonic sensor is manufactured without using a pre-aging routine for the transducer unit.

[0027] Furthermore, foregoing pre-aging of the transducer unit could result in the materials used in the unit exhibiting higher acoustic performance, as performance decreases with age. For example, the materials used in the transducer unit, such as the diaphragm, the transducer, and / or a piece of damping foam, could exhibit greater elasticity than would be the case after hypothetical pre-aging. This could make it possible to generate a given sound pressure level with lower electrical power, thus enabling more energy-efficient operation of the ultrasonic sensor. More elastic materials could also be more sensitive to acoustic vibrations arriving from the air, resulting in higher measurement sensitivity of the ultrasonic sensor in the lower amplitude range.

[0028] Foregoing pre-aging of the transducer unit could also result in a longer overall service life for the ultrasonic sensor, since the materials are not pre-aged but rather in their original, like-new condition at the beginning of the sensor's lifespan. Therefore, the time until a material in the transducer unit reaches its wear limit could be longer than if the transducer unit had been pre-aged during manufacturing. Any potential increase in the aging rate of the transducer unit associated with its new-like condition could be compensated for by regularly performing self-calibration.

[0029] In summary, although foregoing pre-aging might result in the disadvantage of an increased need for self-calibration, this is offset by the technical advantage of a longer overall sensor lifespan and increased sensor efficiency.

[0030] In one example, the configuration shows: Performing an initial calibration of the transducer, the initial calibration having the following characteristics: Measuring a characteristic of the sound transducer; and Storing the measured characteristic as the initial characteristic in an internal memory of the ultrasonic sensor, Programming the ultrasonic sensor with a self-calibration routine, wherein the self-calibration is started by calling the self-calibration routine, the self-calibration routine having: Re-measuring the characteristics of the sound transducer; and Conversion of an output signal from the ultrasonic sensor based on a comparison of the remeasured characteristic with the initial characteristic.

[0031] This could enable reliable compensation for the impact of aging effects in the transducer unit on the ultrasonic sensor's output signal. The transducer characteristic could include measurement data and / or information derived from measurement data, describing the transducer's response to a known excitation signal. For example, the characteristic could be a quantity describing the transducer's response (e.g., a test voltage measured across the diaphragm or a derived quantity), the progression of which is recorded as a function of, for example, the time elapsed since the excitation ceased, the frequency, and / or the amplitude of the excitation signal. The comparison of the remeasured characteristic with the initial characteristic could be based, for example, on key performance indicators and / or a statistical analysis of the characteristic.

[0032] In one application example, the characteristic comprises a time series of a test voltage measured at the diaphragm, and the comparison is based on a time-averaged value or a maximum of the respective time series. For example, if the average or maximum of the remeasured characteristic is 60% smaller than the average or maximum of the initial characteristic, then in this application example, the values ​​of the ultrasonic sensor's output signal (e.g., an output voltage measurable at a sensor interface) can be divided by 0.6 to obtain an output signal scaled to the initial characteristic.

[0033] In another application example, the characteristic curve comprises a measured value of the test voltage for a predefined set of different excitation frequencies or amplitudes. For each excitation frequency or amplitude, the ratio of the respective value of the remeasured characteristic curve to the corresponding value of the initial characteristic curve is calculated, and an average of these quotients is determined. If the average value is, for example, 0.8, the output signal could be divided by 0.8 in this application example to obtain an output signal corresponding to the factory-new condition of the ultrasonic sensor.

[0034] In one example, the energy input is up to 10 percent greater than the theoretically sufficient minimum energy input required to cure the curable material. This could compensate for fluctuations in the energy absorption capacity of the soft component, other components of the converter unit, and / or the assembly containing the converter unit. In this way, complete curing of the curable material could be ensured regardless of these fluctuations, without risking any significant effects on the components of the converter unit beyond the curing of the material itself (such as premature aging). The theoretically sufficient minimum energy input could, for example, be based on literature values ​​and / or calculations and specify an energy quantity corresponding to the amount of material used in the converter unit or the assembly containing the converter unit, which, for example,at least, typically or at most by means of the energy supply to the converter unit or the assembly in order to bring about complete hardening of the hardenable material.

[0035] In one example, the converter unit has several soft components with different curing times, and the energy input is measured to cure only the soft component with the longest curing time. This could ensure that all soft components to be cured are fully cured. The different curing times could, for example, be due to different curable materials contained in the several soft components and / or to different quantities of a identical curable material. If more than one form of energy is used for energy input (e.g., heat and radiation), the curing of the soft component could be carried out separately for at least one or for each of the energy forms used, using the longest curing time for each of the applied energy forms. By combining the possible curing effects of the different energy forms, time savings could also be achieved by shortening the duration(s) required for complete curing.

[0036] In one example, the energy input is determined by a predetermined time profile of power supplied to the converter unit, specifically by a predetermined constant power output over a specified duration. A predetermined time profile could allow for consideration of material-specific responses (e.g., non-constant energy absorption capacity, material-specific thermal conductivity, etc.) of the curable material and / or other materials incorporated into the converter unit and / or an assembly containing the converter unit to the supplied power. In particular, the time profile could be selected to minimize the amount of energy supplied and / or the duration of the energy supply. With a constant power output, the amount of heat supplied could be controlled particularly easily by specifying the duration of the energy supply.

[0037] In one example, the energy input includes a heat input. This could facilitate the simultaneous curing of a large number of ultrasonic sensor assemblies, for example, in an oven or climate chamber. Furthermore, thermal curing could result in energy savings because the heat stored in the components of the heated assembly could be used to complete the curing process, thus allowing the heat input to be terminated earlier. The amount of heat transferred could be controlled, for example, by specifying a temperature profile over time.

[0038] In one example, the heat is added at a temperature that is at least 10 Kelvin below a specified maximum temperature of a procedure assigned to the converter unit for the thermal pre-aging of the converter unit. As a result, If the specified maximum temperature for thermal pre-aging is significantly undercut by at least 10 Kelvin, a possible premature aging of components of the transducer unit caused by the heat input could be reduced, thus optimizing the performance of the ultrasonic sensor (especially the transfer function of the transducer) in its factory-new condition (e.g., at the time of acquisition of the reference data set for self-calibration / the initial characteristic).

[0039] The procedure associated with the transducer unit for thermal pre-aging might be known from previous production periods when thermal pre-aging of ultrasonic sensor assemblies was standard practice. However, it could also be a hypothetical procedure that would have to be applied for thermal pre-aging the assemblies if this were still standard practice. The associated procedure might be specific to the model of the assembly in question (e.g., the components, materials, and / or material quantities used).The procedure could, for example, specify a temperature profile over time to which the assembly containing the transducer unit would be subjected for the full application of thermal pre-aging, for example to minimize the effects of aging of structures, components and / or materials installed in the transducer unit on the output signal of the ultrasonic sensor and / or to achieve the most consistent possible characteristics of different ready-to-use ultrasonic sensors of the given model.

[0040] In one example, the energy input is measured by the time the converter unit reaches a predetermined target temperature for curing. For this purpose, the current temperature could be measured at the converter unit or the assembly containing the converter unit, or, when heating multiple assemblies, at a representative assembly. The target temperature could be chosen such that complete curing of the curable material can be expected when the converter unit or the assembly containing the converter unit reaches this temperature. To prevent exceeding the measured energy input, the heat input could be stopped when the The converter unit has reached the target temperature. In particular, the target temperature could be below the temperature at which the converter unit assumes thermodynamic equilibrium (a constant temperature). In this way, time savings could be achieved compared to tempering the converter unit at a constant temperature. To ensure complete curing of the curable material in all assemblies when curing several assemblies simultaneously, for example in an oven, the temperature could be measured, for instance, on an assembly located in a known coolest area of ​​the oven.

[0041] In one example, heat is supplied through thermal contact between the converter unit and a heat transfer medium that is maintained at the target temperature. This approach could result in energy savings compared to a heat transfer medium whose temperature changes along with the converter unit, due to the reduction of thermal losses. Suitable heat transfer media include fluids such as air, an inert gas, or an inert liquid.

[0042] In one example, the energy input occurs for a duration that is at most 10 percent, preferably at most 5 percent, of a predetermined duration of a procedure assigned to the transducer unit for pre-aging the transducer unit. By significantly reducing the predetermined pre-aging duration by at least 90 percent, any potential premature aging of transducer unit components caused by the energy input could be minimized, thus optimizing the performance of the ultrasonic sensor (especially the transducer's transfer function) in its factory-new state (e.g., at the time of acquiring the reference data set for self-calibration / initial characteristics).

[0043] The procedure associated with the transducer unit for pre-aging the transducer unit might be familiar from previous production periods where pre-aging of ultrasonic sensor assemblies was standard practice. However, it could also be a hypothetical procedure used for pre-aging. The procedure would have to be applied to the assemblies if pre-aging of the assemblies were still performed as a standard practice. The associated procedure could be specific to the model of the assembly in question (e.g., for the components, materials, and / or material quantities used in it). For example, the procedure could specify a performance profile over time to which the assembly containing the transducer unit would be subjected for the full application of pre-aging, for instance, to minimize the effects of aging of structures, components, and / or materials used in the transducer unit on the output signal of the ultrasonic sensor and / or to achieve the most consistent possible characteristics across different operational ultrasonic sensors of the given model.

[0044] In one example, assembly takes place in a continuous production line, with curing being carried out by a curing unit integrated into the line. Integrating the curing unit into the production line could be realistically achieved due to the potentially shorter curing time of, for example, 50–100 minutes compared to pre-aging. Furthermore, compared to processes where, for example, the converter unit or an assembly containing the converter unit is removed from a first section of a production line and fed to a separate pre-aging unit, and, for example, after pre-aging is complete, the converter unit is removed from the pre-aging unit and fed to a second section of the production line, which only resumes production after this interruption, this could significantly simplify the manufacturing process.The manufacturing plant could be continuous in the sense that the converter unit, an assembly comprising the converter unit, or the ultrasonic sensor comprising the converter unit is transferred directly from a manufacturing unit immediately upstream of the curing unit to an input of the curing unit, and that the converter unit, the assembly, or the ultrasonic sensor is transferred directly from the curing unit to an input of a manufacturing unit downstream of the curing unit, provided that the application does not constitute the last manufacturing step of the continuous manufacturing plant.

[0045] The following refers to the drawings, with similar elements being marked with the same reference symbols.

[0046] Figure 1 shows a block diagram schematically illustrating the components of an exemplary ultrasonic sensor 100. It is understood that a real ultrasonic sensor may differ from the ultrasonic sensor 100 shown in Figure 1, for example, by having additional components not shown in Figure 1, and / or by not having components shown in Figure 1, and / or by having components shown in Figure 1 that differ in structural and / or functional features from those disclosed herein for the respective components.

[0047] Components of the ultrasonic sensor 100 could be integrated into a housing 102. The ultrasonic sensor 100 could include an electroacoustic transducer 114, which is designed to convert an ultrasonic space wave propagating in air into a corresponding electromagnetic signal. The transducer 114 could, for example, comprise a diaphragm and an exciter coupled to the diaphragm (e.g., a piezoelectric element). A soft element 116 and other components 118 could also be acoustically coupled to the transducer 114. The soft element 116 could contain a curable material (e.g., polymer-based) that hardens during manufacturing and is no longer plastically deformable after curing. The soft element 116 could, for example, be a damping element that shortens the relaxation time of the vibrating diaphragm, or an adhesive installed near the transducer 114.The additional components 118 could, for example, include electrical connecting wires, a damping component that decouples the housing 102 from acoustic vibrations of the diaphragm, and / or other elements acoustically coupled to the transducer 114. Changes in the mechanical-acoustic properties of the components 116, 118 acoustically coupled to the transducer 114 could affect the vibration behavior of the transducer 114. The components 116, 118 acoustically coupled to the transducer 114 are logically grouped together as a traveling unit 112.

[0048] The components of the transducer unit 112 can be parts of a larger assembly 110, which, in addition to the transducer unit 112, includes further components 119 that are not acoustically coupled to the sound transducer 114, or not significantly so. Insignificant acoustic coupling refers to an acoustic coupling that is physically present but so weak that changes in the mechanical-acoustic properties of the other components 119 do not measurably affect the vibration behavior of the sound transducer 114. The assembly 110 could include all assembled components that are subjected to an energy input 214, sufficient to cure the curable material, for the purpose of applying energy to the transducer unit 112. Besides the assembly 110, the ultrasonic sensor 100 could also include further components 140 that are not subjected to this energy input.

[0049] The ultrasonic sensor 100 could further include a logic 120 and an interface 130. The logic 120 could, for example, comprise an electronic circuit, which is installed on a circuit board and / or provided in the form of one or more integrated circuits. The logic 120 could be configured, among other things, to receive electrical energy via the interface 130 (e.g., via a contacted or contactless electrical transition of the interface 130 with plug(s), socket(s), terminal(s), etc.) and distribute the electrical energy to electrical consumers of the ultrasonic sensor 100, including, for example, components of the transducer unit 112; to receive, digitize, and process an electrical measurement signal generated by the transducer unit 112; to generate an output signal of the ultrasonic sensor 100 based on the received measurement signal and output the output signal via the interface 130 (e.g.,via a contact-based or contactless electrical, optical, ... transition of interface 130); and / or other possible functions, which are not described in detail here for the sake of efficient presentation.

[0050] The logic 120 could in particular be used for one or more processors 122 as well as Memory 124 is connected to the processor 122 for data processing. Memory 124 could, for example, contain firmware 126, among other things. which enables a functional configuration of the logic by means of program instructions executable by the processor 122. The program instructions could, in particular, contain, for example, a program module which, when executed by the processor 122, causes the ultrasonic sensor 100 to perform a self-calibration routine as described herein. The memory 124 could also store a reference data set 128, also referred to herein as the initial characteristic 128. The self-calibration routine could access the reference data set 128 to compare a currently measured calibration data set with the reference data set 128 and, based on this comparison, convert the output signal of the ultrasonic sensor 100 to compensate for changes in the output signal due to aging of components of the transducer unit 112.

[0051] It is understood that the logic 120 and / or the interface 130 can be counted, for example, among the other components 119 of the assembly 110 supplied with energy, or among the components 140 not included in the assembly 110, depending on the chronological order in which the installation of the logic 120 and / or the interface 130 is in relation to the supply 214.

[0052] Figure 2 shows a block diagram schematically illustrating the components of an exemplary continuous production plant 200 for manufacturing ultrasonic sensors 100. It is understood that an actual production plant may differ from the configuration shown in Figure 2, for example, by having additional units not shown in Figure 2, and / or by not having units shown in Figure 2, and / or by having components shown in Figure 2 that differ in structural and / or functional features from those disclosed herein for the respective units.

[0053] In the example shown in Fig. 2, the continuous production plant 200 could have a transport unit 202 that transports assemblies of ultrasonic sensors 100 under production between a series of production units arranged along the transport unit 202 (direction of the arrow). Among the production units could be a first production unit 222, a curing unit 224, and a second production unit 226.

[0054] The production plant 200 could further include a control unit 204, which controls the production units and the transport unit 202 fully or partially by computer. A suitable transmission device 206, such as a bus and / or a computer network, could be used to transmit signals between the control unit 204 and the production units. The control unit 204 could include a computer system with a processor 205 and a memory 207, which stores program instructions. When executed by the processor 205, these instructions cause the control unit 204 to control the production plant 200 in such a way that it carries out the method 210 disclosed herein for manufacturing an ultrasonic sensor 100. The steps of the method 210 assigned to the production units 222, 224, and 226 are shown in Fig. 2 within the dashed line 210.

[0055] In the production of a given ultrasonic sensor 100, the first production unit 222 could be configured and instructed by the control unit 204 to assemble the transducer unit 112. This could be done, for example, by assembling a sub-unit 110 that includes the components of the transducer unit 112. As a result, the first production unit 222 could provide the transducer unit with the soft element 116, which contains the curable material in an uncured state. The first production unit 222 could implement further production steps, not described herein, which also contribute to the production of the ultrasonic sensor 100 in a different way.

[0056] The control unit 204 could then cause the transport unit 202 to transport the converter unit 112, or the assembly 110 comprising the converter unit 112, to the curing unit 224. The production plant 200 could be continuous such that the transport unit 202 transports the converter unit 112, or assembly 110, directly from an output of the first production unit 222 to an input of the curing unit 224, with the movement of the converter unit 112, or assembly 110, remaining under mechanical control by the transport unit 202 during this time. The curing unit 224 could be configured and controlled by the control unit 204 accordingly. The converter unit 112 or the assembly 110 is subjected to an energy input (e.g., thermal, electromagnetic, chemical, acoustic, ...) 214. The amount of energy transferred to the converter unit 112 or the assembly 110 by means of the energy input could be dimensioned such that it causes complete curing of the curable material installed in the converter unit 112, without, however, producing an effect on the converter unit 112 that significantly exceeds the totality of all effects that occur when the converter unit 112 is subjected to the minimum amount of energy required for the complete curing of the curable material.

[0057] The control unit 204 could then cause the transport unit 202 to transport the converter unit 112, or the assembly 110 comprising the converter unit 112, to the second production unit 226. The production plant 200 could be continuous in such a way that the transport unit 202 transports the converter unit 112, or assembly 110, directly from an output of the curing unit 224 to an input of the second production unit 226, with the movement of the converter unit 112, or assembly 110, remaining under mechanical control by the transport unit 202 during this time.The second production unit 226 could be trained and instructed by the control unit 204 to configure the ultrasonic sensor 100 216 so that it is capable of performing a self-calibration, which, as described herein, enables the output signal to always be converted so that it corresponds to the functionality of the transducer unit 112 in its factory-new state. For this purpose, the second production unit 226, unless already done in the first production unit 222, could assemble the transducer unit 112 or the assembly 110 with the logic 120 and / or the interface 130 and program the memory 124 via the interface 130 with program instructions that implement the self-calibration routine.

[0058] Furthermore, the control system 204 could cause the second production unit 226 to perform an initial self-calibration of the converter unit 112, or cause the logic 120 to perform the initial self-calibration. The initial self-calibration could then generate a data record 128 from the The control unit 204 generates measurement data characterizing the vibration behavior of the transducer 114 and / or data derived from the measurement data. This data is permanently stored in the memory 124 and could serve as a basis for future comparisons. These comparisons enable the conversion of the output signal of the ultrasonic sensor 100 to compensate for the effects of aging on the transducer unit 112. It is understood that the control unit 204 could also instruct the second manufacturing unit 226 to implement further manufacturing steps, not described in detail here, which also contribute to the completion of the ultrasonic sensor 100 in a different way.

[0059] Although the invention is illustrated and described in detail in the drawings and the preceding description, this illustration and description is to be regarded as exemplary and not limiting; the invention is not limited to the disclosed embodiments.

[0060] Those skilled in the art will understand that aspects of the present invention may be implemented as a device, a method, or a computer program or computer program product. Accordingly, aspects of the present invention may take the form of a purely hardware embodiment, a purely software embodiment (including firmware, software in memory, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may be generally referred to herein as a "circuit," "module," or "system." Furthermore, aspects of the present invention may take the form of a computer program product, which is carried by one or more computer-readable media in the form of computer-executable code. A computer program also comprises computer-executable code. "Computer-executable code" may also be referred to as "computer program instructions."

[0061] Any combination of one or more computer-readable media may be used. The computer-readable medium may be a computer-readable signaling medium or a computer-readable storage medium. A "computer-readable storage medium," as used herein, comprises a physical storage medium that A computer-readable storage medium can store instructions that can be executed by a processor of a computer device. This computer-readable storage medium can be referred to as a computer-readable non-volatile storage medium. It can also be referred to as a tangible computer-readable medium. In some embodiments, a computer-readable storage medium may also be capable of storing data that allows access to it by the processor of the computer device. Examples of computer-readable storage media include, but are not limited to: a floppy disk, a magnetic hard disk, a solid-state drive, flash memory, a USB flash drive, random access memory (RAM), read-only memory (ROM), an optical disk, a magneto-optical disk, and the processor's register file.Examples of optical discs include Compact Discs (CDs) and Digital Versatile Discs (DVDs), such as CD-ROM, CD-RW, CD-R, DVD-ROM, DVD-RW, or DVD-R discs. The term computer-readable storage medium also refers to various types of recording media suitable for retrieval by a computer device via a network or communication link. For example, data can be retrieved via a modem, the internet, or a local area network. Computer-executable code running on a computer-readable medium may be transmitted via any suitable medium, including but not limited to wireless, wired, fiber optic, RF, etc., or any suitable combination of the foregoing media.

[0062] A computer-readable signal medium can contain a propagated data signal that includes the computer-readable program code, for example, in a baseband signal or as part of a carrier signal (carrier wave). Such a propagation signal can be in any form, including, but not limited to, an electromagnetic form, an optical form, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium that is not a computer-readable storage medium and that can transmit, propagate, or transport a program for use by or in conjunction with a system, device, or apparatus for executing instructions.

[0063] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory that is directly accessible to a processor.

[0064] "Computer data storage" or "data storage" is another example of a computer-readable storage medium. Computer data storage is any non-volatile, computer-readable storage medium. In some embodiments, computer memory can also be computer data storage, or vice versa.

[0065] A “processor,” as used herein, comprises an electronic component capable of executing a programmatically or machine-executable instruction or computer-executable code. References to the computing device comprising a “processor” should be interpreted to mean that it may include more than one processor or processing cores. The processor may, for example, be a multi-core processor. A processor may also refer to a collection of processors within a single computer system or distributed across multiple computer systems. The term computing device or computer should also be interpreted to mean, possibly, a collection or network of computing devices or computers, each comprising a processor or processors.The computer executable code can be executed by multiple processors, which may be located within the same computer device or even distributed across multiple computers.

[0066] Computer-executable code may comprise machine-executable instructions or a program that causes a processor to perform an aspect of the present invention. Computer-executable code for performing operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, Smalltalk, C++, or similar languages, and conventional procedural programming languages ​​such as the programming language "C" or similar programming languages, and translated into machine-executable instructions. In some cases, the computer-executable code may be in the form of a higher-level programming language or in a pre-translated form, and in It can be used in conjunction with an interpreter that displays the machine-executable code. Instructions generated.

[0067] The computer executable code can run entirely on a user's computer, partially on the user's computer as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, via the internet using an internet service provider).

[0068] Computer program instructions can be executed on one processor or on multiple processors. In the case of multiple processors, these can be distributed across several different entities (e.g., clients, servers). Each processor could execute a portion of the instructions intended for its respective entity. Therefore, when referring to a system or procedure that encompasses multiple entities, the computer program instructions are understood to be adapted to be executed by a processor assigned to or associated with each entity.

[0069] Aspects of the present invention are described with reference to flowchart representations and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the invention. It is pointed out that each block or parts of the blocks of the flowcharts, representations, and / or block diagrams can be executed by computer program instructions, optionally in the form of computer-executable code. It is further pointed out that combinations of blocks in different flowcharts, representations, and / or block diagrams can be combined, provided they are not mutually exclusive. These computer program instructions can be issued to a processor of a general-purpose computer, a specialized computer, or another programmable computer. A data processing device shall be provided to create a device such that the instructions executed through the processor of the computer or other programmable data processing device shall generate means for performing the functions / steps specified in the block or blocks of the flowcharts and / or block diagrams.

[0070] These computer program instructions may also be stored on a computer-readable medium capable of controlling a computer or other programmable data processing equipment or other devices to function in a particular manner, such that the instructions stored on the computer-readable medium produce a manufactured product, including instructions that implement the function / step specified in the block(s) of the flowcharts and / or block diagrams.

[0071] The computer program instructions can also be stored on a computer, other programmable data processing devices, or other devices to cause the execution of a series of process steps on the computer, other programmable data processing devices, or other devices to generate a process executed on a computer, such that the instructions executed on the computer or other programmable devices generate procedures for implementing the functions / steps specified in the block or blocks of the flowcharts and / or block diagrams. TI LIST OF REFERENCE MARKS 100 ultrasonic sensors 102 cases 110 assembly 112 converter unit 114 transducers 116 Soft element 118 components (converter unit) 119 components (assembly) 120 Logic 122 processor 124 memory 126 Firmware 128 program instructions 130 interface 140 components (sensor) 200 production plant 202 transport units 204 Control unit 205 processor 207 storage 210 procedures Step 212 “Assembly” Step 214 “Pressure” Step 216 “Configure” 222 First production unit 224 Curing unit 226 Second production unit

Claims

REQUIREMENTS 1. Method (210) for manufacturing an ultrasonic sensor (100), wherein the method (210) comprises: Assembling (212) a transducer unit (112) of the ultrasonic sensor (100), wherein the transducer unit (112) comprises an electroacoustic sound transducer (114) and a soft component (116), wherein the soft component (116) comprises a curable material; Applying (214) to the converter unit (112) an energy input dimensioned for curing the curable material; and Configuring (216) the ultrasonic sensor (100) to perform a self-calibration to compensate for aging of the transducer unit (112).

2. Method (210) according to claim 1, wherein the configuration comprises: Performing an initial calibration of the sound transducer (114), wherein the initial calibration exhibits: Measuring a characteristic of the sound transducer (114); and Storing the measured characteristic as an initial characteristic (128) in an internal memory (124) of the ultrasonic sensor (100), programming the ultrasonic sensor (100) with a self-calibration routine, wherein the self-calibration is started by calling the self-calibration routine, the self-calibration routine having: Re-measuring the characteristics of the sound transducer (114); and converting an output signal of the ultrasonic sensor (100) based on a comparison of the re-measured characteristics with the initial characteristics (128).

3. Method (210) according to claim 1 or 2, wherein the energy input is up to 10 percent greater than a minimum energy input that is theoretically sufficient to cure the curable material.

4. Method (210) according to one of the preceding claims, wherein the converter unit (112) has several soft components (116) with different curing times, wherein the energy input is dimensioned such that it causes curing of one of the soft components (116) which has the longest curing time.

5. Method (210) according to one of the preceding claims, wherein the energy supply is measured by a predetermined time profile of a power supplied to the converter unit (112), in particular by a predetermined constant power over a predetermined time period.

6. Method (210) according to one of the preceding claims, wherein the energy supply comprises a heat supply.

7. Method (210) according to claim 6, wherein the heat supply takes place at a temperature that is at least 10 Kelvin below a predetermined maximum temperature of a procedure for thermally pre-aging the converter unit (112) associated with the converter unit (112).

8. Method (210) according to claim 6 or 7, wherein the energy input is measured such that the converter unit (112) has reached a target temperature predetermined for curing.

9. Method (210) according to one of the preceding claims, wherein the assembly (212) takes place in a continuous production plant (200), wherein the application (214) is carried out by a curing unit (224) integrated into the continuous production plant (200).

10. Computer program product, in particular a computer-readable storage medium that stores computer-executable code, wherein the code is executable by at least one processor (205) of a computer device (204) in order to to cause a computer device (204) to control a plant (200) for manufacturing ultrasonic sensors (100) in order to carry out a method (210) for manufacturing an ultrasonic sensor (100), wherein the method (210) comprises: Assembling (212) a transducer unit (112) of the ultrasonic sensor (100), wherein the transducer unit (112) comprises an electroacoustic sound transducer (114) and a soft component (116), wherein the soft component (116) comprises a curable material; Applying (214) to the converter unit (112) an energy input dimensioned for curing the curable material; and Configuring (216) the ultrasonic sensor (100) to perform a self-calibration to compensate for aging of the transducer unit (112).

11. Computer system (204) comprising a processor (205) and a memory (207) functionally connected to the processor (205), wherein the memory (207) stores computer-executable code, wherein, when executed by the processor (205), the code causes the computer system (204) to control a plant (200) for manufacturing ultrasonic sensors (100) in order to execute a method (210) for manufacturing an ultrasonic sensor (100), wherein the method (210) comprises: Assembling (212) a transducer unit (112) of the ultrasonic sensor (100), wherein the transducer unit (112) comprises an electroacoustic sound transducer (114) and a soft component (116), wherein the soft component (116) comprises a curable material; Applying (214) to the converter unit (112) an energy input dimensioned for curing the curable material; and Configuring (216) the ultrasonic sensor (100) to perform a Self-calibration to compensate for aging of the converter unit (112).

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