CN113960608A

CN113960608A - Ultrasonic measurement device for detecting structures around a mobile device using dirac pulses in the frequency domain

Info

Publication number: CN113960608A
Application number: CN202110800683.9A
Authority: CN
Inventors: 托马斯·罗伊尔
Original assignee: Elmers Semiconductor Europe
Current assignee: Elmers Semiconductor Europe
Priority date: 2020-07-21
Filing date: 2021-07-15
Publication date: 2022-01-21
Also published as: DE102020119242A1; DE102020119242B4

Abstract

The invention relates to an ultrasonic sensor device for a mobile device, in particular a robot and/or a vehicle and/or a missile and/or an aircraft, for detecting and characterizing objects in the surroundings of the mobile device, having a long range of action and the ability to evaluate strong frequency distortions. The ultrasonic sensor device comprises a conventional narrow-band ultrasonic transmitter, preferably piezoelectric, such as is used today, for example, in motor vehicles for parking assistance and which usually exhibits a high radiated acoustic power, and at least one, preferably a plurality of, MEMS ultrasonic receivers, which usually have a large frequency bandwidth. By using the frequency bandwidth of the MEMS ultrasound receiver, the distortion can be better evaluated and converted into a map of the surroundings of the vehicle. Preferably, the second frequency bandwidth of the MEMS ultrasound receiver is equal to or greater than the value obtained by multiplying the first frequency bandwidth of the ultrasound transmitter by a factor of 2 and/or 5 and/or 10 and/or 20 and/or 50 and/or 100.

Description

Ultrasonic measurement device for detecting structures around a mobile device using dirac pulses in the frequency domain

Technical Field

The invention relates to an ultrasonic sensor device for a mobile device, in particular a robot and/or a vehicle and/or a missile and/or an aircraft, for detecting and characterizing objects in the vicinity of the mobile device, having a long range of action and the ability to evaluate strong frequency distortions.

Background

The use of ultrasonic transducers to assist parking processes and the like is well known in automotive technology. A problem with the ultrasound transducers used in the prior art is their narrow bandwidth, which firstly limits the possible modulation of the transmitted ultrasound signal and secondly limits the possibility of obtaining additional information from signal distortions. Furthermore, in the prior art, if the ultrasonic receiver is not designed as a piezoelectric driven solid metal resonator, there is a risk of damage by stone impact when the ultrasonic receiver is used in a vehicle. MEMS ultrasonic receivers are not used in automotive technology due to the low sound output power and the concomitant short range of action and sensitivity to stone strikes.

However, for narrow-band ultrasound receivers which are currently used as ultrasound transducers in motor vehicles, the analysis of the vehicle surroundings in the frequency domain is not meaningful.

Disclosure of Invention

It is therefore an object of the present invention to create a solution which does not have the above-mentioned drawbacks of the prior art and which has other advantages.

This object is achieved by a device according to claim 1.

Detailed Description

Elaborating on the proposal presented herein is due to the recognition that: in many applications other than automotive applications, the ultrasonic sensors and the stone strike resistance of the ultrasonic sensor elements required in motor vehicles are not required at all. Such mobile devices without this requirement are for example forklift trucks, robots and drones, or other mobile devices used indoors and/or outdoors at low speeds below 10km/h, and other low airspeed (<100km/h) missiles.

For an optimal measurement of the surroundings of such a mobile device, a large range of action is desired in the first place. For this purpose, the ultrasound transmission power of the ultrasound transmitter should be as high as possible. Ultrasonic transducers and pure ultrasonic transmitters having a metallic can (Metalltopf) vibrated in the mechanical resonance range by a piezoelectric vibrating element are demonstrated herein. Preferably, the mechanical resonance frequency of the metal can is equal to the resonance frequency of the piezoelectric vibrating element. Preferably, the sound radiates in the direction of the bottom and passes through the bottom of the metal can. Preferably, the piezoelectric vibrating element is fastened to the bottom of the tank, for example, by a conductive adhesive. In this respect, reference is made, by way of example, to patent DE 102015015900B 3 and the documents cited therein.

Generally, such piezoelectric ultrasonic transducers have a relatively high quality in terms of their resonance. The resonance spectrum of these ultrasonic transducers is generally broadened only by the emitted acoustic power. If these ultrasonic transducers are used to receive waves backscattered by objects in the environment surrounding the mobile device, they can only vibrate poorly, since the reflection of the ultrasound on objects in the environment surrounding the mobile device attenuates and distorts the ultrasound, which leads to a broadening of the original narrow-band spectrum of the radiated ultrasound.

Therefore, on the one hand, it is necessary to radiate a strong narrow-band ultrasound wave and, on the other hand, to receive the reflected ultrasound wave as broadband as possible.

Today's ultrasound systems in mobile devices primarily take into account the propagation time of the pulse-shaped envelope of an ultrasound pulse train (ultrashall-Bursts) consisting of a plurality of successive ultrasound pulses.

With the teachings presented herein, it is now possible to extend the length of the ultrasound burst without terminating the operational capabilities of the ultrasound sensor system.

In contrast, in extreme cases, it is even possible to consider transmitting an ultrasound continuous wave signal and to evaluate only the distortion of the reflected and/or transmitted ultrasound signal received by one or more ultrasound receivers. In implementing the present invention, it has been recognized that this requires a very broadband ultrasound receiver. Ultrasonic transducers of the above-mentioned type are therefore unsuitable for this due to the high quality of the resonance spectrum.

The idea is therefore to use dirac pulses in the frequency domain to sample the reflection spectrum of the vehicle environment in this frequency domain, reconstruct the environmental spatial spectrum in the spatial frequency domain from the reflection spectrum, and then convert the spatial spectrum determined in this way back into the environmental map of the vehicle.

Now, in practicing the present invention, it has been recognized that MEMS microphones with high receive bandwidths are particularly suitable for the application.

Thus, in effect, the ultrasound receiver transmits a time series of ultrasound bursts. An ultrasound burst consists of a time sequence of one or more ultrasound pulses. The instantaneous frequency in the ultrasound pulse train is the inverse of the duration from the level value of an ultrasound pulse in the ultrasound pulse train having a rising or falling direction to the same level value of the immediately following ultrasound pulse in the ultrasound pulse train having the same rising or falling direction.

The instantaneous frequency may change during the ultrasound burst. Thus, an ultrasound burst typically has an instantaneous frequency profile of instantaneous frequencies. Thus, the ultrasound burst has an ultrasound burst duration. The ultrasound burst duration begins at the first edge of the first ultrasound pulse in the ultrasound burst and ends at the last edge of the last pulse in the ultrasound burst. Since the ultrasound transducer of the transmitted ultrasound burst has a high Q value, the ability to modulate the ultrasound burst in terms of amplitude and phase is limited. By using a broadband receiver, the ultrasound burst duration can be increased without having to reduce the resolution in the close range directly in front of the mobile device.

In establishing the present invention, it has been recognized that: if the vehicle is assumed to be used in a controlled, stone-free environment or only at low speeds, a MEMS microphone may be used due to the omission of stone impact resistance. Thus, it is now possible to use dirac pulses in the frequency domain instead of in the time domain and to use them to scan the spatial spectrum of the reflectivity of the environment surrounding the mobile device in the frequency or spatial frequency domain.

Since the manufacturing cost of the ultrasonic MEMS microphones (especially as an array) is very low, it is very feasible to use more ultrasonic MEMS microphones to scan the temporal/spatial spectrum. More MEMS microphones can increase the spatial frequency used for scanning in the spatial frequency domain. For such a scanning point in the spatial frequency domain, a plurality of ultrasonic MEMS microphones are preferably mounted on the outer surface of the mobile device spaced apart from each other. Preferably, the separation distance is chosen such that the expected frequency of the reflected back ultrasound waves results in a measurable phase shift at the location of the ultrasound MEMS microphones in combination with the expected direction of incidence of the ultrasound waves. These phase shifts should preferably be in the range of 0 to 2 pi.

Since the reflected ultrasound waves can thus be received in a wide band in the form of one or more reflected ultrasound pulse trains, the spatial properties of the environment can then be deduced from different distortion analyses of the ultrasound waves when they are received by different ultrasound MEMS microphones.

Of course, different propagation times can also be understood as distortions. However, doppler distortion of the environment surrounding the mobile device and other characteristics that distort the spectrum of the returned ultrasound waves are also detected, and conventional systems cannot detect these characteristics because of the small bandwidth.

Therefore, an ultrasonic sensor device for a mobile device, in particular a robot and/or a vehicle and/or a missile and/or an aircraft, is proposed, which serves to detect and characterize objects in the surroundings of the mobile device and has a large range of action and the ability to evaluate strong frequency distortions. The proposed ultrasonic sensor device comprises one or more ultrasonic transmitters and at least one ultrasonic receiver, but preferably a plurality of ultrasonic receivers spaced apart from each other. Preferably, therefore, the ultrasonic sensor device and the ultrasonic transmitter and ultrasonic receiver comprised by it are part of a mobile device. Ultrasound transmitters are typically designed to transmit ultrasound waves into the surroundings of the mobile device. Preferably, these ultrasound waves comprise said ultrasound bursts, which are preferably spaced apart from each other in time when emitted by a single ultrasound transmitter, and comprise one or more ultrasound pulses spaced apart from each other in time. Furthermore, the proposed ultrasound sensor device comprises a control and evaluation device which detects and evaluates the output signal of the ultrasound receiver and controls the ultrasound transmitter. Furthermore, the control evaluation device signals the evaluation result of this evaluation to the user and/or to a superordinate or secondary computer system for further use. If necessary, instead of or in addition to the signal, an actuator of the mobile device (e.g. a rotor of the drone and/or a motor of the robot) may also be controlled depending on the evaluation result.

A typical broadband ultrasound receiver within the meaning of the present invention is for example a MEMS microphone. Such an ultrasonic receiver is generally manufactured from a semiconductor crystal, and generally has a micromechanical diaphragm as its vibrating element. Then, the incident ultrasonic wave may vibrate the vibration element. Various methods for detecting the vibration of a micromechanical membrane are known from the prior art. The first method uses piezoresistive sensors on or in the micromechanical membrane. Piezoresistive sensors change their resistance value according to the mechanical stress acting on them. They are preferably connected in a wheatstone bridge. When the micromechanical membrane is bent, a bending stress is generated, which leads to a detuning of the wheatstone bridge and thus to a differential signal at the output of the wheatstone bridge, which can be evaluated as a differential output signal by the control evaluation device of the ultrasonic sensor device. The second method uses a capacitive MEMS microphone. In the case of this method, the capacitance between the micromechanical membrane or its part as the first electrode and the reference electrode is measured and detected by controlling the evaluation device. In this case, the differential signal is also evaluated by controlling the evaluation device. A third approach uses a structured piezoelectric layer on the membrane. The occurring bending moments cause forces to be exerted on the piezoelectric layer, resulting in a voltage signal which can be detected via contacts on the piezoelectric layer and evaluated as an output signal by controlling an evaluation device. If the micromechanical membrane is now in vibration (which may be caused, for example, by an incident reflected ultrasonic signal), these mechanical vibrations can be detected electrically and converted into an output signal of the ultrasonic receiver. If necessary, the ultrasound receiver may also comprise its own signal processor, which may be considered as part of the control evaluation device of the ultrasound sensor device. For example, it is conceivable that such signal processing in connection with the respective ultrasound receiver transforms, amplifies, filters and, if necessary, compresses the raw signals of the actual sensor elements (for example the output signals of the wheatstone bridge). The measured values transmitted by the output signal of the ultrasonic receiver are therefore dependent on the vibrations and/or deflections of the micromechanical membrane of the ultrasonic receiver. Such MEMS-based ultrasound receivers are typically constructed in one piece. The signal evaluator may be micro-integrated in the ultrasound receiver. However, it may also be located on another semiconductor crystal in a common housing with the micromechanical microphone. The signal processor for such sensor elements may also be located in a central processor, if necessary. In the latter case, the ultrasound receiver then comprises only the actual sensor unit with the micromechanical membrane and the electromechanical converter unit according to the above-described conversion method.

In contrast, the piezoelectric vibrating element of an ultrasonic transmitter is provided with a typically pot-shaped resonator body to which the piezoelectric vibrating element is acoustically and/or mechanically coupled, directly or indirectly. The resonator body is preferably a pot-shaped metal equipment part, the diameter of which is preferably of the order of the resonance frequency of the ultrasound transmitter in a multiple of half the ultrasound wave length in the resonator body material. The resonator body generally interacts with a piezoelectric vibration element, so that the piezoelectric vibration element can mechanically vibrate the pot resonator body. Here, the resonance spectrum of the pot resonator in the ultrasound transmitter exhibits resonance at a first resonance frequency having a first frequency bandwidth. The ultrasound receiver includes a sensitivity spectrum having a second frequency bandwidth. The control and evaluation device vibrates the pot resonator of the ultrasound transmitter by means of the piezoelectric vibration element of the ultrasound transmitter, so that the ultrasound waves are emitted in the form of one or more ultrasound pulse trains. The ultrasonic receiver then receives the ultrasonic waves, directly or indirectly, respectively, and converts them into corresponding ultrasonic receive signals as its output signals, in particular after reflection and/or distortion by one or more objects in the environment surrounding the mobile device. The control evaluation device evaluates these ultrasound reception signals of the ultrasound receiver. In the simplest case, the ultrasound sensor system comprises only one ultrasound receiver. The control evaluation device and/or the downstream device now draw conclusions about the environmental and/or object properties in the moving environment from the ultrasound receive signals obtained in this way and generally taking into account the time profile of the originally emitted ultrasound waves.

Although the burst duration may be very long, in order to be able to deduce the position, size and nature of objects in the environment surrounding the mobile device, the ultrasound receiver now has a particularly high frequency bandwidth, which allows good detection of distortions. According to the invention, the second frequency bandwidth of the ultrasound receiver is therefore equal to or greater than the value of the first frequency bandwidth of the ultrasound transmitter multiplied by a factor 2 and/or better by a factor 5 and/or better by a factor 10 and/or better by a factor 20 and/or better by a factor 50 and/or better by a factor 100.

Within the meaning of this document, the frequency bandwidth of the ultrasound transmitter should be determined such that the impedance spectrum is determined by driving the ultrasound transmitter with an electrical transmission signal having an excitation frequency, wherein the excitation frequency is tuned to determine the electrical impedance of the ultrasound transmitter for the excitation frequency. The main maximum of the conductance generally occurs together with the conductance maximum. The frequency at which this main maximum occurs is the resonance frequency. At higher and lower frequencies, the conductance drops towards the base value (Sockelwert). Thus, a 50% ultrasonic transmitter conductance may be determined, the 50% ultrasonic transmitter conductance being determined as the half of the difference between the conductance maximum and the base value plus the base value to obtain the value. The ultrasonic transmitter exhibits the 50% ultrasonic transmitter conductance at the first frequency and the second frequency. Within the meaning of this document, the amount of difference between the first frequency value and the second frequency value is the frequency bandwidth of the ultrasound transmitter.

Within the meaning of this document, the frequency bandwidth of an ultrasound receiver should be determined in the following manner: an ultrasonic receiver is irradiated with ultrasonic waves having a known excitation frequency and a known excitation amplitude, and a value profile of the output signal is determined for the excitation frequency and the excitation amplitude. From which the transfer function of the ultrasound receiver can be determined. The transfer function generally includes a main maximum of the amplitude of the transfer function when the transfer function has a maximum. The frequency at which this main maximum occurs is the resonance frequency of the ultrasonic receiver. At higher and lower frequencies, the value of the transfer function decreases towards the receiver base value. Unfortunately, this drop does not always decrease monotonically. However, it is also possible here to determine a 50% ultrasonic receiver value, which is determined as the value obtained by adding the receiver base value to half the difference between the maximum transfer function value and the receiver base value. The ultrasonic receiver exhibits the 50% ultrasonic reception value at the third frequency and the fourth frequency. Within the meaning of this document, the amount of difference between the fourth frequency value and the third frequency value is the frequency bandwidth of the ultrasound receiver.

In the first described variant of the teachings herein, the one or more ultrasonic receivers are MEMS microphones, the operating principle of which is based on a capacitance change caused by interaction with the ultrasonic waves acting on the respective MEMS microphone, and the respective output signals of which depend on parameters of the acting ultrasonic waves, such as amplitude and/or frequency. In this case, the control and evaluation device comprises means for operating such a MEMS microphone and for detecting and processing the output signal of the MEMS microphone. Such a device may be, for example, a capacitance measuring device. Such a capacitance measuring device may for example comprise an oscillator which uses the measuring capacitance of the micromechanical diaphragm to be measured as a measuring capacitance and which generates a measuring signal, for example by mixing an output signal of the oscillator with an output signal of a reference oscillator, the signal of which measuring signal can be detected with a simple counter.

In the second described variant of the teachings herein, the one or more ultrasonic receivers of the ultrasonic sensor device are MEMS microphones, the operating principle of which is based on a change in resistance caused by interaction with the ultrasonic waves acting locally on the respective MEMS microphone, in particular on the basis of the piezoresistive effect, and the respective output signals of which depend on the parameters of the ultrasonic waves of this action, such as amplitude, frequency and phase. Here, the control and evaluation device also comprises means for operating the MEMS microphone and for detecting and processing the output signal of the MEMS microphone. In general, the component can be, for example, a regulated voltage source for the excitation voltage of the preferably used wheatstone bridge and an amplifier with differential inputs for generating the output signal.

In the third described variant of the teachings herein, the one or more ultrasonic receivers of the ultrasonic sensor device are MEMS microphones, the operating principle of which is based on the generation of a voltage by interaction with an ultrasonic wave acting locally on the respective MEMS microphone, in particular on the basis of the piezoelectric effect, and the respective output signals of which depend on the parameters of the ultrasonic wave acting.

The control and evaluation device also comprises means for operating the MEMS microphone and for detecting and processing the respective output signal of the MEMS microphone. Such a device may generally be an amplifier which detects the respective voltage generated, adjusts the operating point appropriately if necessary, in each case amplifies the voltage and thus generates and outputs a respective output signal.

In order to be able to build and evaluate a phased array, it is advantageous if the mobile device and thus the ultrasound sensor device has a plurality of ultrasound receivers spaced apart from one another, and the evaluation device is controlled to evaluate the output signals of these ultrasound receivers in order to deduce the properties of objects in the surroundings of the mobile device and/or of the surroundings of the mobile device. The control evaluation device transmits the result of this evaluation to the user and/or the superordinate device or uses it to control the actuators of the mobile device. In particular, the actuator may be a driver of the mobile device.

Preferably, after and/or during the time window during which the ultrasonic waves are emitted (which is preferably taken into account in the subsequent evaluation), the control evaluation device detects the output signal of the ultrasonic receiver, which is transmitted by the ultrasonic receiver in compressed and/or uncompressed form to the control evaluation device. The time window may be, for example, a hamming window.

The control evaluation device then transforms the output signals detected in this way (for example with the aid of a hamming window), which are usually present as time samples (after decompression if necessary), from the time and spatial domain into the spatial frequency domain and the time-frequency domain, so that they can subsequently be used as spectral samples. This then yields the co-transformed output signal spatio-temporal spectrum in the form of a set of spectral samples. The control and evaluation device can then divide the jointly transformed output signal space-time spectrum, which is usually composed of discrete spectral sample values, obtained in this way in pairs by a reference space-time spectrum in the form of reference values in order to obtain a corrected output signal space-time spectrum in the form of corrected spectral sample values. The control and evaluation device then transforms the corrected output signal space-time spectrum in the form of corrected spectral sample values back into the corrected time-space domain in the form of time samples in order to deduce a spatial structure function.

Of particular interest is that the transmitted ultrasound burst does not have a stable instantaneous frequency. The frequency of the reflected ultrasonic signal reaching the ultrasonic receiver is therefore a measure of the acoustic path traveled.

However, this frequency may be distorted by doppler shift and air disturbances, which can cause a prolonged acoustic path. In addition to the transit time from the envelope of the received ultrasound pulse train, it is also possible to draw conclusions about the acoustic distance from the reflecting object and its reflection intensity from the frequency components in the output signal spectrum of the ultrasound receiver.

Preferably, these measurements are repeated and combined with previous measurements to give a result with better confidence. For this purpose, the ultrasound signal comprises an ultrasound pulse train with a large number of ultrasound pulses, which are preferably repeated. As mentioned above, the aim is to scan the surroundings of the mobile device with pulses in the frequency domain that are as dirac-pulse-shaped as possible and to determine the spatial and temporal frequency response to the dirac-pulse. To this end, at least one ultrasound burst (hereinafter referred to as frequency dirac burst) in the sequence of ultrasound bursts comprises at least 10 and/or at least 20 and/or at least 50 and/or at least 100 and/or at least 200 and/or at least 500 and/or at least 1000 ultrasound pulses.

Advantages of the invention

The advantages are not limited thereto.

Claims

1. An ultrasonic sensor device for a mobile device, in particular a robot and/or a vehicle and/or a missile and/or an airplane, for detecting and characterizing objects in the surroundings of the mobile device, having a long range of action and the ability to evaluate strong frequency distortions, having:

an ultrasonic transmitter;

at least one ultrasonic receiver; and

the evaluation device is controlled so as to control the evaluation device,

wherein the ultrasonic transmitter has a resonance spectrum, and

wherein the resonance spectrum of the ultrasonic transmitter has resonance at a first resonance frequency having a first frequency bandwidth, and

wherein the ultrasonic receiver has a sensitivity spectrum having a second frequency bandwidth, and

wherein the second frequency bandwidth of the ultrasonic receiver is equal to or greater than a value obtained by multiplying the first frequency bandwidth of the ultrasonic transmitter by a factor of 2 and/or 5 and/or 10 and/or 20 and/or 50 and/or 100,

it is characterized in that the preparation method is characterized in that,

the ultrasonic receiver is a MEMS microphone whose operating principle is based on a change in resistance caused by interaction with an ultrasonic wave acting on the MEMS microphone, in particular on the piezoresistive effect, and whose output signal depends on a parameter of the ultrasonic wave acting, and

the control and evaluation device comprises means for operating the MEMS microphone and for detecting and processing the output signal of the MEMS microphone.

2. The ultrasonic sensor device of claim 1,

wherein the ultrasonic sensor device comprises a plurality of ultrasonic receivers spaced apart from each other, and

wherein the control evaluation device evaluates the output signals of the ultrasound receiver in order to infer objects in the surroundings of the mobile device and/or characteristics of the surroundings of the mobile device.

3. The ultrasonic sensor device of claim 2,

in a time window after and/or during the transmission of the ultrasonic waves, the control and evaluation device detects the output signal of the ultrasonic receiver, which is transmitted by the ultrasonic receiver to the control and evaluation device in compressed and/or uncompressed form, and

the control and evaluation device transforms the output signals obtained in this way, optionally after decompression, from the time and space domain into the spatial frequency domain and the time frequency domain, resulting in a jointly transformed output signal spatio-temporal spectrum, and

the control and evaluation device divides the jointly transformed output signal spatio-temporal spectrum by a reference spatio-temporal spectrum to obtain a corrected output signal spatio-temporal spectrum, and

the control and evaluation device transforms the corrected output signal spatio-temporal spectrum back to the spatio-temporal domain to infer a spatial environment structure function.

4. The ultrasonic sensor device of any one or more of claims 1 to 3,

wherein the ultrasonic transmitter transmits an ultrasonic signal, and

wherein the ultrasound signal comprises an ultrasound pulse train having a plurality of ultrasound pulses, and

wherein at least one ultrasonic burst, called frequency dirac burst, comprises at least 10 and/or at least 20 and/or at least 50 and/or at least 100 and/or at least 200 and/or at least 500 and/or at least 1000 ultrasonic pulses.

5. The ultrasonic sensor device of claim 4,

wherein the control evaluation device detects the output signal of the ultrasonic receiver during reception of the frequency dirac pulse train and evaluates the output signal by evaluating a frequency spectrum of the output signal to infer characteristics of the surrounding environment of the mobile device.

6. An ultrasonic sensor device for a mobile device, in particular a robot and/or a vehicle and/or a missile and/or an airplane, for detecting and characterizing objects in the surroundings of the mobile device, having a long range of action and the ability to evaluate strong frequency distortions, having:

an ultrasonic transmitter;

at least one ultrasonic receiver; and

the evaluation device is controlled so as to control the evaluation device,

wherein the at least one ultrasonic receiver comprises a vibrating element, the oscillation of which is electrically detectable and the output signal of which depends on the vibrating element, and

wherein the at least one ultrasonic receiver is integrally made, in particular as a microelectromechanical device, also referred to as MEMS device, and

wherein the vibration element of the ultrasonic transmitter is provided with a pot-shaped resonating body, and

wherein the tank-shaped resonant body interacts with the vibration element such that the vibration element can mechanically vibrate the tank-shaped resonant body, and

wherein a resonance spectrum of the pot resonator in the ultrasonic transmitter has resonance at a first resonance frequency having a first frequency bandwidth, and

wherein the control evaluation apparatus oscillates the tank-shaped resonating body of the ultrasonic transmitter and transmits an ultrasonic wave by the vibration element of the ultrasonic transmitter, and

in particular after reflection and distortion of the ultrasonic waves by one or more objects in the surroundings of the mobile device, the ultrasonic receiver receives the ultrasonic waves directly or indirectly and converts them into ultrasonic reception signals, and

wherein the control evaluation device evaluates the ultrasound reception signals and

wherein the control evaluation device and/or downstream device infers a characteristic of the surrounding environment and/or a characteristic of an object in the surrounding environment of the mobile device, and

wherein the second frequency bandwidth of the ultrasonic receiver is equal to or greater than a value of the first frequency bandwidth of the ultrasonic transmitter multiplied by a factor of 2 and/or 5 and/or 10 and/or 20 and/or 50 and/or 100,

it is characterized in that the preparation method is characterized in that,

the ultrasonic receiver is a MEMS microphone whose operating principle is based on a change in resistance caused by interaction with the ultrasonic waves acting on the MEMS microphone, in particular on the piezoresistive effect, and whose output signal depends on a parameter of the ultrasonic waves acting, and

7. The ultrasonic sensor device of claim 6,

8. The ultrasonic sensor device of claim 7,

9. The ultrasonic sensor device of any one or more of claims 6 to 8,

wherein the ultrasonic transmitter transmits an ultrasonic signal, and

10. The ultrasonic sensor device of claim 9,

11. An ultrasonic sensor device for a mobile device, in particular a robot and/or a vehicle and/or a missile and/or an airplane, for detecting and characterizing objects in the surroundings of the mobile device, having a long range of action and the ability to evaluate strong frequency distortions, in particular according to claim 1, having:

an ultrasonic transmitter;

at least one ultrasonic receiver; and

the evaluation device is controlled so as to control the evaluation device,

wherein the control evaluation apparatus oscillates the tank-shaped resonating body of the ultrasonic transmitter and transmits an ultrasonic wave through the piezoelectric oscillation element of the ultrasonic transmitter, and

the ultrasonic receiver receives the ultrasonic waves directly or indirectly, in particular after reflection and distortion by one or more objects in the surroundings of the mobile device, and converts the ultrasonic waves into ultrasonic reception signals, and

it is characterized in that the preparation method is characterized in that,

the ultrasonic sensor device includes a plurality of ultrasonic receivers spaced apart from each other, and

the control evaluation device evaluates the output signals of the ultrasound receiver in order to infer objects in the surroundings of the mobile device and/or properties of the surroundings of the mobile device, and

12. The ultrasonic sensor device of claim 11,

wherein the ultrasonic receiver is a MEMS microphone whose operating principle is based on a capacitance change caused by an interaction with an ultrasonic wave acting on the MEMS microphone, and whose output signal depends on a parameter of the ultrasonic wave acting, and

wherein the control and evaluation device comprises means for operating the MEMS microphone and for detecting and processing the output signal of the MEMS microphone.

13. The ultrasonic sensor device of claim 11,

wherein the ultrasonic receiver is a MEMS microphone whose operating principle is based on a change in resistance, in particular on the piezoresistive effect, caused by interaction with an ultrasonic wave acting on the MEMS microphone, and whose output signal depends on a parameter of the ultrasonic wave acting, and

wherein the control evaluation device comprises means for operating the MEMS microphone and for detecting and processing the output signal of the MEMS microphone.

14. The ultrasonic sensor device of claim 11,

wherein the ultrasonic receiver is a MEMS microphone whose operating principle is based on the generation of a voltage caused by an interaction with an ultrasonic wave acting on the MEMS microphone, in particular on the piezoelectric effect, and whose output signal depends on a parameter of the ultrasonic wave acting, and

15. The ultrasonic sensor device of any one or more of claims 11 to 14,

wherein the ultrasonic transmitter transmits an ultrasonic signal, and

16. The ultrasonic sensor device of claim 15,

17. An ultrasonic sensor device, in particular according to claim 1, for a mobile device, in particular a robot and/or a vehicle and/or a missile and/or an aircraft, for detecting and characterizing objects in the surroundings of the mobile device, having a long range of action and the ability to evaluate strong frequency distortions, the ultrasonic sensor device having:

an ultrasonic transmitter;

at least one ultrasonic receiver; and

the evaluation device is controlled so as to control the evaluation device,

wherein the ultrasonic transmitter has a resonance spectrum, and

it is characterized in that the preparation method is characterized in that,

the control evaluation device evaluates the output signal of the ultrasound receiver in order to infer objects in the surroundings of the mobile device and/or properties of the surroundings of the mobile device, and

18. The ultrasonic sensor device of claim 17,

19. The ultrasonic sensor device of claim 17,

20. The ultrasonic sensor device of claim 17,

21. The ultrasonic sensor device of any one or more of claims 17 to 20,

wherein the ultrasonic transmitter transmits an ultrasonic signal, and

22. The ultrasonic sensor device of claim 21,