CN117441111A - Object recognition using ultrasonic sensors in case of crosstalk - Google Patents

Abstract

The invention relates to a method for identifying an object (24), in particular in the surroundings (26) of a vehicle (10), using an ultrasonic sensor (16) having at least a first and a second ultrasonic signal-receiving channel, wherein the identification of the object (24) takes place on the first receiving channel for receiving ultrasonic echoes (30, 34), comprising the following steps: receiving ultrasonic signals on the first and second receiving channels in accordance with at least one transmitted ultrasonic pulse (28); identifying a first ultrasonic echo having a first amplitude in the ultrasonic signal in a first receive path; a first ultrasound echo (30) for crosstalk inspection based on the ultrasound signal received on the second receive channel; and in case of a negative result of the crosstalk check, outputting an identification of the object (24) for the identified first ultrasound echo (30). The invention also relates to an ultrasonic sensor (16) for identifying an object (24), which is designed to carry out the above-described method for identifying an object (24). The invention also relates to an ultrasound recognition system (12) for recognizing an object (24), in particular an object (24) in the environment (26) of a vehicle (10), having a plurality of ultrasound sensors (16) with at least a first and a second receiving channel for ultrasound signals and a controller (14), which are connected to one another by a data link (22), wherein the ultrasound recognition system (12) is designed to carry out the above-described method for recognizing an object (24).

Description

Object recognition using ultrasonic sensors in case of crosstalk

Technical Field

The invention relates to a method for identifying an object, in particular an object in the environment of a vehicle, using an ultrasonic sensor having at least a first receiving channel and a second receiving channel for ultrasonic signals, wherein the identification of the object is performed for receiving ultrasonic echoes on the first receiving channel.

The invention also relates to an ultrasonic sensor for identifying an object, in particular in the environment of a vehicle, having at least a first receiving channel and a second receiving channel for ultrasonic signals, wherein the identification of the object is performed on the first receiving channel for receiving ultrasonic echoes, wherein the ultrasonic sensor is designed to perform the above-described method for identifying an object.

The invention further relates to an ultrasonic recognition system for recognizing objects, in particular objects in the surroundings of a vehicle, using a plurality of ultrasonic sensors having at least a first and a second receiving channel for ultrasonic signals, and a controller, which are connected to one another via a data link, wherein for at least one ultrasonic sensor an object recognition is performed on the first receiving channel for receiving ultrasonic echoes, and wherein the ultrasonic recognition system is designed to use the at least one ultrasonic sensor to perform the above-described method for recognizing objects.

Background

The ultrasonic sensor emits ultrasonic pulses that are reflected as ultrasonic echoes by objects in the environment. These ultrasonic echoes may be received by an ultrasonic sensor to detect the distance from the object to the ultrasonic sensor from the time difference between the transmission of the ultrasonic pulse and the reception of the ultrasonic echo.

Such ultrasonic sensors are currently used in many vehicles to perform various functions, such as detecting parking space, measuring parking space, monitoring distance from an obstacle during a parking maneuver, or monitoring blind spots of the vehicle while driving.

However, in the case of an ultrasonic recognition system having a plurality of ultrasonic sensors arranged in groups, for example, arranged in the front and/or rear of a vehicle, problems may occur if the ultrasonic sensors receive false ultrasonic echoes. These false ultrasonic echoes may occur when an ultrasonic sensor receives an ultrasonic signal or receives an ultrasonic echo based on them from an ultrasonic sensor and assigns them to different ultrasonic sensors as ultrasonic echoes (e.g., self-emitted ultrasonic pulses). This problem is exacerbated when multiple ultrasonic sensors are designed to receive ultrasonic echoes based on ultrasonic pulses emitted by the ultrasonic sensors. To reduce these problems, it is known to operate ultrasonic sensors, for example, at different frequencies and/or with a time delay, so as to make the ultrasonic echoes distinguishable.

Furthermore, the use of ultrasonic sensors is known, which receive ultrasonic echoes simultaneously on a plurality of channels. The channels are defined, for example, by frequency shifting and/or by different modulations (chirp up)/chirp down) and are tuned to receive ultrasound echoes in the respective channels, for example in a narrow frequency band. Thus, the ultrasonic sensor can receive and distinguish between, for example, simultaneously transmitted ultrasonic pulses or ultrasonic echoes based thereon in two channels. The ultrasonic pulses may be emitted, for example, by two adjacent ultrasonic sensors or by a receiving ultrasonic sensor and an adjacent ultrasonic sensor. Despite the channel separation, a certain degree of crosstalk may occur between the two channels, which makes the ultrasound echo visible not only on the appropriate channel but also on the other channel. Such spurious ultrasound echoes can then be assigned to incorrect ultrasound sources, i.e. incorrect ultrasound sensors, which can lead to errors in object recognition.

In this respect, a distance detection device is known from DE 199 24 755a1 for detecting the distance of an object by means of a wave signal emitted by the distance detection device and reflected by the object. The distance detection device comprises a transmitting/receiving device for transmitting and receiving wave signals, which has at least a first and a second spatially separated transmitting and/or receiving unit, a first one of the first and the second spatially separated transmitting and/or receiving unit having at least one transmitting function and a second one each having at least one receiving function. The two units are designed such that the second unit can receive the wave signal emitted by the first unit as a crosstalk signal and the first unit or the second unit can receive the wave signal emitted by the first unit as a reflection signal. The distance detection device further comprises an interference determination device for confirming at least one characteristic parameter of the crosstalk signal received in the second unit and for determining the interference based on the confirmed characteristic parameter.

Document DE 10 2005 062 539 A1 relates to a method for calibrating a sensor system using a transmitter and a receiver mounted on a vehicle at a distance from each other to measure the distance between the measuring vehicle and the road boundary, using the following steps: (a) Transmitting a transmit signal at a first time using a transmitter of the sensor system; b) Converting the received transmitted signal into a received signal using a receiver of the sensor system and establishing a second time when the received signal exceeds a certain threshold; c) Determining a propagation time of the transmitted signal from the transmitter to the receiver based on a time difference between the second time and the first time; d) Cyclically repeating a) to c) for a certain number of cycles; e) Determining a frequency distribution of the propagation times determined in step c), and f) generating a sensor distance value, which is related to the sensor propagation time between the transmitter and the receiver, using the frequency distribution determined in e).

Document EP 1 517 157 B1 discloses a method for distance measurement, which uses at least two contactless distance sensors (in particular ultrasonic sensors). Each distance sensor has a transmitter for transmitting measurement pulses and a receiver for receiving measurement pulse echoes, wherein the distance to an obstacle reflecting the measurement pulses is determined from the time difference between the measurement pulses and the received measurement pulse echoes. The measurement pulse is transmitted by the first and second distance sensors for a time shift of the initial measurement and the measurement pulse echo is received by the first distance sensor. A tolerance reception time range is defined around the received measurement pulse echo. If a second time-shifted transmission of measurement pulses by the first and second distance sensors is performed, wherein the time delay between the measurement pulses transmitted by the first and second distance sensors is changed compared to the initial measurement for the verification measurement, by correlating the measurement receive signal obtained in the initial measurement with the measurement receive signal received in the verification measurement, a directly reflected measurement pulse echo can be identified if it is received within a tolerance reception time range during the verification measurement.

EP 2 090 897 B1 relates to a driver assistance system of a vehicle, which has a controller which is connected via a data bus to a plurality of sensors arranged on the vehicle in a data exchange active connection. Sensor signals for generating signal echoes are transmitted such that previously known logical addresses of each sensor can be assigned to predefined locations of the sensor. The sensor signal is an ultrasonic signal.

Disclosure of Invention

It is therefore an object of the present invention, starting from the above-mentioned prior art, to specify a method for identifying objects, in particular objects in the surroundings of a vehicle, which uses an ultrasonic sensor having at least a first and a second receiving channel for ultrasonic signals, an ultrasonic sensor for carrying out the method, and an ultrasonic identification system comprising a controller and a plurality of ultrasonic sensors for carrying out the method, which enable an improved identification of objects using the ultrasonic sensor and which help to avoid false identifications of objects, in particular in the case of crosstalk.

According to the invention, this object is achieved by the features of the independent claims. Advantageous configurations of the invention are defined in particular in the dependent claims.

The invention therefore in particular defines a method for identifying an object, in particular an object in the surroundings of a vehicle, using an ultrasonic sensor having at least a first and a second receiving channel for ultrasonic signals, wherein the identification of the object is performed for receiving ultrasonic echoes on the first receiving channel, the method comprising the steps of: receiving ultrasonic signals on a first receiving channel and a second receiving channel from at least one transmitted ultrasonic pulse, detecting a first ultrasonic echo having a first amplitude in the ultrasonic signals on the first receiving channel, checking the first ultrasonic echo for crosstalk based on the reception of the ultrasonic signals on the second receiving channel, and outputting an object identification for the detected first ultrasonic echo in case of a negative result of the crosstalk check.

The invention also particularly defines an ultrasonic sensor for identifying an object, in particular an object in the surroundings of a vehicle, having at least a first receiving channel and a second receiving channel for ultrasonic signals, wherein the identification of the object is performed for receiving ultrasonic echoes on the first receiving channel, wherein the ultrasonic sensor is designed to perform the above-described method for identifying an object.

Furthermore, the invention particularly defines an ultrasonic recognition system for recognizing objects, in particular objects in the surroundings of a vehicle, which ultrasonic recognition system uses a plurality of ultrasonic sensors having at least a first receiving channel and a second receiving channel for ultrasonic signals and a controller which are connected to one another via a data link, wherein for at least one of the ultrasonic sensors an object recognition is performed for receiving ultrasonic echoes on the first receiving channel, and wherein the ultrasonic recognition system is designed to use the at least one ultrasonic sensor to perform the above-described method for recognizing objects.

The basic idea of the invention is thus to verify the ultrasound echo received on the first reception channel on the basis of the ultrasound signal received on the second reception channel. When cross-talk occurs in the other channel, there are corresponding ultrasound echoes on the first and second receive channels. If the basis is an ultrasonic signal that does not belong to the first or second reception channel, crosstalk can also be detected and thus be generated on the first and second reception channels. However, in general, the second receiving channel is formed by a channel on which another ultrasonic sensor transmits an ultrasonic pulse as a transmission channel, so that crosstalk from the channel to the first receiving channel can be selectively detected. When the first ultrasound echo is checked for crosstalk, for example, the ultrasound signals received on the first and second receive channels may be compared to determine whether the ultrasound signal on the second receive channel contains a signal corresponding to the first ultrasound echo of the first receive channel. Thus, if there is a similar signal waveform or a similar ultrasound echo on both receive channels at the same time, this can be detected as an indication of crosstalk.

The detection of crosstalk may be used to detect the first ultrasound echoes based on crosstalk from another channel so that they are not processed as identified objects. This can improve driving safety and the functionality of various driving assistance systems up to and including the function for automatic driving.

In an ultrasound identification system, when multiple ultrasound sensors are used together, it may be the case that only one of the channels is used to receive ultrasound echoes at the ultrasound frequency. Depending on the current configuration of the ultrasound recognition system and the resulting configuration of the ultrasound sensors. In particular, in the case of an ultrasonic sensor that does not use a reception channel to identify an object, the reception channel may be used to identify a first ultrasonic echo caused by crosstalk without limiting the function of the corresponding ultrasonic sensor or ultrasonic identification system.

The ultrasonic sensors of the ultrasonic recognition system are preferably arranged along the side of the vehicle, for example along the front and/or rear of the vehicle.

The method is based on receiving an ultrasonic signal on each receive channel. The receive channel also typically corresponds to a transmit channel on which the one or more ultrasonic sensors transmit ultrasonic pulses. In this respect, the definition is in principle independent of transmission or reception, and thus both types are commonly referred to as channels. Therefore, there is no technical difference between the reception channel and the transmission channel.

Channels are defined, for example, by frequency shifting and/or by different modulations (chirping up/chirping down) and are tuned to receive ultrasound echoes in the respective channels (e.g. in a narrow frequency band). For example, the ultrasonic sensor may be designed with receiving channels of different frequencies. For example, the first receive channel may be located at a center frequency of 51kHz, while the second receive channel is an upper or lower channel having, for example, 51+/-3 kHz.

Preferably, the method is repeatedly performed in order to check all relevant ultrasound echoes of the ultrasound signal received on the first reception channel for crosstalk.

If there are more than two receive channels, the detected ultrasound echoes can thus be checked for crosstalk for multiple receive channels. For example, with three reception channels, two of the reception channels may be used as a first reception channel for identifying an object, and the remaining reception channels are used as a second reception channel, so as to check whether there is crosstalk in the first ultrasonic echoes of the two first reception channels. This is possible in a particularly reliable manner for the frequency shift channels, for example if the second receiving channel is located between the two first receiving channels.

In an ultrasound recognition system, ultrasound sensors on one side of the vehicle (e.g., on the front or rear) may each be connected to a controller. Thus, a plurality of autonomous ultrasonic recognition systems may be formed and used on a vehicle. Preferably, the vehicle comprises an ultrasound recognition system, wherein all ultrasound sensors are connected to only one controller.

In an ultrasound identification system, an ultrasound sensor is connected to a controller via a data link. The data link is preferably designed as a data bus to which all ultrasonic sensors and controllers are connected. Different protocols and topologies may be used for this purpose. A data bus system commonly used in the automotive field is known as CAN, flexRay, LON and the like.

The above method may be performed entirely in a separate ultrasonic sensor. All that is required is to set the ultrasonic sensor to the desired receiving channel. With such an arrangement, more than one of the ultrasound sensors can operate together in the ultrasound identification system without requiring changes in operation compared to known ultrasound sensors. The setting may be performed at any given time or as a fixed setting. The output of object recognition may be generated by the ultrasonic sensor by, for example, outputting the received first ultrasonic echo. Alternatively, an envelope curve of the received ultrasound signal may be output, wherein the first ultrasound pulse based on crosstalk is masked.

In the ultrasonic recognition system that performs the above-described method, in the case of a negative result of the crosstalk inspection, object recognition for the detected first ultrasonic echo is output by the controller. Thus, in principle, known ultrasound sensors with multiple receiving channels can be used to perform the method in an ultrasound identification system.

In an advantageous embodiment of the invention, the checking the first ultrasound echo for crosstalk based on the reception of the ultrasound signal on the second reception channel comprises: detecting a second ultrasonic echo corresponding to the detected first ultrasonic echo and having a second amplitude in the ultrasonic signal of the second receiving channel, and comparing the first amplitude with the second amplitude, wherein the first ultrasonic echo is identified as cross-talk if the first amplitude is less than the second amplitude. In particular, if the crosstalk is based on an ultrasonic signal generated on the second receiving channel, the crosstalk can be detected by comparing the amplitudes of ultrasonic echoes detected on the two receiving channels. Thus, a first ultrasound echo on the first receive channel having a smaller amplitude than a corresponding second ultrasound echo on the second receive channel may be reliably detected as crosstalk from the second receive channel to the first receive channel. Conversely, if the first amplitude is greater than the second amplitude, it is verified that the crosstalk is not the source of the first ultrasound echo. The opposite is true for crosstalk from the first receive channel to the second receive channel.

In an advantageous embodiment of the invention, detecting a second ultrasound echo corresponding to the detected first ultrasound echo and having a second amplitude in the ultrasound signal of the second receiving channel comprises: the reception of the second ultrasound echo is detected within a reception interval from the reception of the first ultrasound echo. In order for the first ultrasound echo to be crosstalk-based and thus identified, a corresponding second ultrasound echo must be present. This can be verified by receiving the second ultrasound echo in close temporal relationship to the first ultrasound echo. The time relationship may be defined and verified by the receive interval. For example, the reception interval is aligned with the reception time of the first ultrasound echo, in particular time-symmetrical with respect to the maximum amplitude of the first ultrasound echo. Alternative locations of the receiving interval are possible. The width of the receiving interval may be selected to ensure a close temporal relationship between the first ultrasound echo and the second ultrasound echo. For example, the receive interval may have four times, preferably twice, the length of a typical ultrasonic pulse transmitted by the ultrasonic recognition system.

In an advantageous embodiment of the invention, identifying the first ultrasound echo as crosstalk if the first amplitude is smaller than the second amplitude comprises: the first ultrasonic echo is identified as cross-talk if the first amplitude is less than the second amplitude by about one channel spacing or more between the first receive channel and the second receive channel. In particular, in the case of crosstalk due to simultaneous use of multiple channels, the source of the crosstalk is known such that the crosstalk can be detected by a corresponding amplitude difference having at least a tolerance range in terms of size. Crosstalk depends on the configuration of the channels, such as frequency spacing and channel width. In an ultrasonic sensor, for example, for a center frequency of 51kHz and upper and lower channels having, for example, 51+/-3kHz, a channel spacing in the range of 4-5dB between the center frequency and the upper or lower channel can be obtained. The channel spacing between the upper and lower channels is typically 16-17dB. Thus, if the first and second amplitudes differ by about the channel spacing, depending on the receiving channel used, crosstalk can be assumed.

In an advantageous embodiment of the invention, the ultrasound sensor for identifying an object is designed to receive ultrasound echoes on a second receiving channel, and the method comprises the step of checking the second ultrasound echoes for crosstalk based on the reception of the ultrasound signals on the first receiving channel, wherein checking the second ultrasound echoes for crosstalk comprises detecting a first ultrasound echo corresponding to a detected second ultrasound echo in the ultrasound signals of the first receiving channel, and comparing a second amplitude with the first amplitude, wherein the second ultrasound echo is identified as crosstalk if the second amplitude is smaller than the first amplitude. Thus, a mutual check of crosstalk between the first and second reception channels can be performed. In this case, when the corresponding first ultrasonic echo and second ultrasonic echo appear on the first receiving channel and the second receiving channel, only the ultrasonic echo having a larger amplitude is output as the identification of the object. Thus, time-shifted ultrasound echoes on the first ultrasound channel and the second ultrasound channel can be processed separately and output as an identification of the object, whereas in the case of the first ultrasound echo and the second ultrasound echo having a close temporal relationship, only the ultrasound echo having a larger amplitude is output as an identification of the object. When the channel interval between the first reception channel and the second reception channel is considered, the first ultrasonic echo and the second ultrasonic echo having similar amplitudes (i.e., having amplitudes that differ by less than the channel interval) can be output as the correct identification of the object.

In an advantageous embodiment of the invention, the method comprises the step of providing a first and a second receiving channel. This allows flexible use of the ultrasonic sensor, e.g. for different applications, or to be able to check cross-talk between different receiving channels. For example, if a first receive channel has a center frequency, a second receive channel may switch between channels having higher and lower frequencies to alternately check for crosstalk from both channels.

In an advantageous embodiment of the invention, the first receiving channel and the second receiving channel for the ultrasound signal are distinguished by a frequency shift and/or by different modulations, for example as chirped up or chirped down. Other and/or further differences in channels are possible than defining channels via their frequencies. A chirp up or a chirp down refers to a signal whose frequency varies with time. A distinction is made between a chirp up in frequency with increasing time and a chirp down in frequency with decreasing time.

In an advantageous embodiment of the invention, the ultrasound recognition system is designed to send the ultrasound signals received with the at least one ultrasound sensor on the first receiving channel to the controller, wherein the controller is designed to detect a first ultrasound echo of the ultrasound signals of the first receiving channel having a first amplitude, and/or the ultrasound recognition system is designed to send the ultrasound signals received with the at least one ultrasound sensor on the second receiving channel to the controller. Wherein in particular the controller is designed to detect a second ultrasound echo having a second amplitude, which corresponds to the detected first ultrasound echo in the ultrasound signal of the second reception channel. This means that a distributed execution of the method takes place, wherein the ultrasonic sensor receives an ultrasonic signal and the controller checks the first ultrasonic echo for crosstalk based on the reception of the ultrasonic signal on the second reception channel and outputs an object identification for the detected first ultrasonic echo in case of a negative result of the crosstalk check. The one or more ultrasonic sensors may transmit the received ultrasonic signal as an envelope curve to the controller, for example, wherein the controller detects in this case a first ultrasonic echo having a first amplitude in the transmitted ultrasonic signal of the first reception channel. The ultrasonic sensor may transmit ultrasonic signals of only one or both of the two receive channels in a specified manner, wherein the controller may identify the first and/or second ultrasonic echoes in the ultrasonic signals from the first and second receive channels, respectively.

In an advantageous embodiment of the invention, the at least one ultrasonic sensor is designed to detect a first ultrasonic echo having a first amplitude in the ultrasonic signal of the first receiving channel and to send the detected first ultrasonic echo to the controller, wherein the at least one ultrasonic sensor is preferably further designed to detect a second ultrasonic echo corresponding to the detected first ultrasonic echo and having a second amplitude in the ultrasonic signal of the second receiving channel and to send the detected second ultrasonic echo to the controller, wherein the controller is designed to check the first ultrasonic echo for crosstalk based on the reception of the ultrasonic signal on the second receiving channel. This means that here too a distributed execution of the method takes place, wherein the ultrasonic sensor receives an ultrasonic signal and the controller checks the first ultrasonic echo for crosstalk based on the reception of the ultrasonic signal on the second reception channel and outputs an object identification for the detected first ultrasonic echo in the case of a negative result of the crosstalk check. Thus, the one or more ultrasonic sensors may send information about the detected first ultrasonic echo and/or second ultrasonic echo to the controller, i.e. the amplitude level, transit time (transit time) and/or propagation time of the respective ultrasonic echo with absolute time stamp.

In principle, the two embodiments described above can be combined. However, preferably, only one of the variants is implemented in the ultrasound recognition system, i.e. all received ultrasound signals are sent to the controller, or for all received ultrasound signals only detected ultrasound echoes are sent to the controller.

In an advantageous embodiment of the invention, the ultrasound recognition system is designed to transmit ultrasound pulses on a first transmission channel using a first ultrasound sensor and to perform a method for recognizing an object using an adjacent ultrasound sensor, wherein the first transmission channel preferably corresponds to a first reception channel. This means that an ultrasonic signal from another ultrasonic sensor is received, ensuring that no cross-talk based ultrasonic echo is output.

The ultrasonic sensor itself, which performs the method for identifying an object, may also emit ultrasonic pulses on the first transmission channel.

In an advantageous embodiment of the invention, the ultrasound recognition system is designed to emit ultrasound pulses substantially simultaneously on a second transmission channel using a second ultrasound sensor, wherein the second ultrasound sensor is arranged adjacent to or preferably at a distance from the ultrasound sensor performing the method for recognizing an object, wherein particularly preferably the second transmission channel corresponds to the second receiving channel. Thus, crosstalk can be specifically checked by ultrasonic pulses emitted by the second ultrasonic sensor on the second transmission channel. If the second ultrasonic sensor is arranged at a distance from the ultrasonic sensor performing the method for identifying an object, crosstalk can already be reduced. Additional crosstalk inspection may further reduce incorrect object recognition. Thus, the second ultrasonic sensor represents a source of crosstalk, wherein detection of crosstalk may reduce the output of incorrect recognition of the object.

In an advantageous embodiment of the invention, the ultrasound recognition system is designed to modify the configuration of the ultrasound sensor to the first and/or second ultrasound sensor and/or to the ultrasound sensor which performs the method for recognizing the object during operation, in particular after each measurement cycle in which an ultrasound pulse is transmitted with the first and/or second ultrasound sensor. This allows the adjustment of the ultrasound identification system to be performed so that the surrounding environment can be detected in the same way, irrespective of the function of the ultrasound sensor for receiving ultrasound echoes in a given measurement cycle. The configuration of only some individual ultrasonic sensors may be partially modified, or all ultrasonic sensors may be completely modified.

The above comments about the method for identifying an object can be transferred to the ultrasound sensor and/or the ultrasound identification system accordingly, and vice versa.

The invention is explained in more detail below with reference to the drawings on the basis of preferred embodiments. The features shown may each represent an aspect of the invention, both individually and in combination. Features of different exemplary embodiments may be transferred from one exemplary embodiment to another.

Drawings

Figure 1 shows a schematic view of a vehicle with an ultrasound recognition system for recognizing objects in the surroundings of the vehicle according to a first preferred embodiment,

figure 2 shows a schematic diagram of the reception of a first ultrasound echo and a second ultrasound echo on a first receiving channel and a second receiving channel using the ultrasound identification system of figure 1,

figure 3 shows a schematic view of receiving a second ultrasound echo on a second receiving channel using the ultrasound recognition system of figure 1,

fig. 4 shows a schematic diagram of receiving first and second ultrasonic echoes on first and second receive channels using the ultrasonic identification system of fig. 1, wherein the first ultrasonic echo is based on crosstalk,

FIG. 5 shows a schematic diagram of receiving a first ultrasound echo on a first receive path using the ultrasound recognition system of FIG. 1, an

Fig. 6 shows a flow chart of a method for identifying an object, which method is performed using the ultrasound identification system from fig. 1.

Detailed Description

Fig. 1 shows a vehicle 10 having an ultrasonic identification system 12 according to a first preferred embodiment.

The ultrasound recognition system 12 includes a controller 14 and a plurality of ultrasound sensors 16. The ultrasonic sensors 16 are arranged in two sets of six ultrasonic sensors 16 each along the front 18 and rear 20 of the vehicle 10. The ultrasonic sensor 16 and the controller 14 are connected together via a data link 22. The data link 22 is designed here as a data bus 22, to which data bus 22 all ultrasonic sensors 16 and the controller 14 are connected. Different protocols and topologies may be used for this purpose, as is known in the art. In the exemplary embodiment, data bus 22 is implemented in accordance with one of the standards CAN, flexRay, or LON.

The ultrasonic sensor 16 is designed to identify an object 24 in the surrounding environment 26 of the vehicle 10 and is disposed on the vehicle 10. Each of the ultrasonic sensors 16 is designed with an adjustable transmission channel for transmitting ultrasonic pulses 28 having a beam angle α, as is explicitly shown in fig. 1 for the ultrasonic sensor 16 on the rear 20 of the vehicle 10. In addition, each of the ultrasonic sensors 16 is designed with a first and a second adjustable reception channel for receiving ultrasonic signals, wherein in the present case the identification of the object 24 is performed at least for the reception of the first ultrasonic echo 30 on the first reception channel. In this exemplary embodiment, the first and second receive channels differ by a frequency shift. In this exemplary embodiment, the receiving channel of the ultrasonic sensor may be set to a center frequency of about 51kHz, or to upper and lower channels having upper and lower frequencies of 51+/-3kHz, respectively.

The following text describes a method of identifying an object 14 in the surrounding environment 26 of the vehicle 10 using the ultrasonic identification system 12 of the first exemplary embodiment described with reference to fig. 1.

The method begins at step S100, where ultrasonic pulses 28 are transmitted by the ultrasonic sensor 16 of the ultrasonic recognition system 12 at step S100. An exemplary configuration for transmitting ultrasonic pulses 28 with the ultrasonic sensor 16 of the ultrasonic recognition system 12 is shown in FIG. 1. The configuration of the ultrasonic sensors 16 for the front 18 and rear 20 portions is mirrored, which is why the remaining description is limited to the operation of the ultrasonic sensors 16 on the front 18 of the vehicle 10, but applies correspondingly to the ultrasonic sensors 16 on the rear 20 of the vehicle 10.

As shown in fig. 1, the upper first ultrasonic sensor 16, which is additionally marked with S1, emits an ultrasonic pulse 28 having a frequency f1, the frequency f1 being here the center frequency of the ultrasonic sensor 16. Thus, the frequency f1 defines a first transmission channel set for the first ultrasonic sensor 16, S1. The second ultrasonic sensor 16, additionally labeled with S2, emits substantially simultaneously ultrasonic pulses 28 having a frequency f2, where f2 is the lower frequency of the ultrasonic sensor 16. Therefore, the frequency f2 defines a second transmission channel set for the second ultrasonic sensor 16, S2. The third ultrasonic sensor 16, additionally labeled with S3, emits substantially simultaneously ultrasonic pulses 28 having a frequency f3, where f3 is the upper frequency of the ultrasonic sensor 16. Therefore, the upper frequency f3 defines a third transmission channel set for the third ultrasonic sensor 16, S3.

The ultrasonic sensor 16 arranged directly below the first ultrasonic sensor 16, S1 and at a distance from the second ultrasonic sensor 16, S2 is also considered here by way of example, and the rest of the method for identifying the object 24 is explained by way of example.

Step S110 involves receiving ultrasonic signals on the first and second receive channels in accordance with ultrasonic pulses 28 emitted by the first and second ultrasonic sensors 16, S1, 16, S2. For this purpose, the first receiving channel of the ultrasonic sensor 16 is set to the center frequency f1, and the second receiving channel of the ultrasonic sensor 16 is set to the lower frequency f2. Thus, the first receiving channel corresponds to the first transmission channel and the second receiving channel corresponds to the second transmission channel. In this exemplary embodiment, the identification of the object 24 is performed based on the ultrasonic signal received on the first reception channel.

Step S120 involves transmitting the ultrasonic signals received on the first and second receiving channels with the ultrasonic sensor 16 to the controller 14. In the exemplary embodiment, ultrasonic sensor 16 transmits the received ultrasonic signal as an envelope curve to controller 14. Prior thereto, the received ultrasonic signal may be amplified or otherwise processed in the ultrasonic sensor 16 in a known manner to provide an envelope curve.

Step 130 involves detecting a first ultrasound echo 30 having a first amplitude 32 in the ultrasound signal of the first receive channel. The detection is based on the shape of the envelope curve. The first ultrasound echo 30 is detected as a peak in the envelope curve having a first amplitude. The first amplitude 32 corresponds to the maximum value of the amplitude of the first ultrasound echo 30 in the envelope curve, wherein the ultrasound signal of the first receiving channel may contain further first ultrasound echoes 30.

In a first exemplary embodiment, the controller 14 detects a first ultrasound echo 30 having a first amplitude 32.

Step 140 involves checking for crosstalk of the first ultrasound echo 30 based on receipt of the ultrasound signal on the second receive path.

In accordance with the above-described detection of the first ultrasonic echo 30 having the first amplitude 32, first a second ultrasonic echo 34 having a second amplitude 36 corresponding to the detected first ultrasonic echo 30 is detected in the ultrasonic signal of the second receiving channel. In the first exemplary embodiment, a second ultrasonic echo 34 having a second amplitude 36 is also detected by the controller 14. As shown in fig. 1, the second ultrasonic echo 34 having the second amplitude 36 is based on the ultrasonic pulse 28 emitted by the second ultrasonic sensor 16, S2.

In addition, it is checked whether the detected second ultrasound echo 34 corresponds in time to the detected first ultrasound echo 30. For this purpose, it is specifically checked whether the second ultrasound echo 34 is received within a reception interval 38 from the reception of the first ultrasound echo 30. The reception interval 38 is aligned with the reception time of the first ultrasound echo 30, in particular time-symmetrical with respect to the maximum amplitude of the first ultrasound echo 30. The width of the receiving interval 38 is selected to ensure a tight time relationship between the first ultrasound echo 30 and the second ultrasound echo 34.

If the detected second ultrasound echo 34 corresponds in time to the detected first ultrasound echo 30, a comparison of the amplitudes 32, 36 of the two ultrasound echoes 30, 34 is performed. If the first amplitude 32 is less than the second amplitude 36 of the second ultrasound echo 34, the first ultrasound echo 30 is detected as cross-talk.

To illustrate this, fig. 2-5 illustrate receiving first and second ultrasound echoes 30, 34 having first and second amplitudes 32, 36 on first and second receive channels.

Fig. 2 shows the reception of a first ultrasound echo 30 having a first amplitude 32 and a second ultrasound echo 34 having a second amplitude 36. The first ultrasound echo 30 is detected at a distance of 0.5m and the second ultrasound echo 34 is detected at a distance of 0.52m, such that the second ultrasound echo 34 is received within the receiving interval 38. The first amplitude 32 of the first ultrasound echo 30 is greater than the second amplitude 36 of the second ultrasound echo 34. Thus, the first ultrasound echo 30 is not caused by crosstalk, but by the object 24, and is thus output in a subsequent step S150.

Fig. 3 shows a scenario in which only a second ultrasound echo 34 having a second amplitude 36 is received. The second ultrasound echo 34 is detected at a distance of 0.52 m. The receiving interval 38 is not defined here, since no first ultrasound echo 30 is detected which can be used as a basis for locating the receiving interval 38. Since only the object 24 for the first receive channel is detected here, the second ultrasound echo 34 is not processed further.

Fig. 4 shows the reception of a first ultrasound echo 30 having a first amplitude 32 and a second ultrasound echo 34 having a second amplitude 36. The first ultrasound echo 30 is detected at a distance of 0.48m and the second ultrasound echo 34 is detected at a distance of 0.5m, such that the second ultrasound echo 34 is received within the receiving interval 38. The first amplitude 32 of the first ultrasound echo 30 is less than the second amplitude 36 of the second ultrasound echo 34. The first ultrasound echo 30 is thus caused by crosstalk, which in the prior art results in the detection of reflections of the ultrasound signal 28 emitted by the second ultrasound sensor 16, S2 as a ghost object 40. By detecting the crosstalk, the output of the identification of the object 24 based on the first ultrasound echo 30 in the subsequent step S150, i.e. the identification of the object 24 is not output, is adjusted accordingly.

Fig. 5 shows a scenario in which only a first ultrasound echo 30 having a first amplitude 32 is received. The first ultrasound echo 30 is detected at a distance of 0.52 m. The second ultrasound echo 34 is not detected in the receiving interval 38. Thus, the first ultrasound echo 30 is not caused by crosstalk, but by the object 24, and is thus output in a subsequent step S150. Therefore, the "ghost object" 40 is not located within the range of the beam angle α of the ultrasonic pulse 28 of the second ultrasonic sensor 16, S2.

Step 150 involves outputting an identification of the object 24 for the detected first ultrasound echo 30 in case of a negative result of the cross-talk check. Only in the above case, where the detected first ultrasound echo 30 has been tested as no (negative for crosstalk) for crosstalk, a corresponding output is thus produced, which here comprises the distance of the first ultrasound echo 30 and its amplitude.

Preferably, the method is repeated with steps S130 to S150 to detect further first ultrasound echoes 30 on the first receiving channel and to check for crosstalk.

Step S160 involves changing the configuration of the ultrasonic sensor 16. Thus, for example, the configuration of the ultrasonic sensor 16 on the front 18 may be adjusted to the configuration of the ultrasonic sensor 16 on the rear 20 of the vehicle 10 shown in FIG. 1, and vice versa. As a result, different configurations of the ultrasonic sensors 16 are provided as the first, second, and third ultrasonic sensors 16, S1, 16, S2, 16, S3 and as the ultrasonic sensor 16 that performs the method for identifying the object 24. The configuration of the ultrasonic sensor 16 may be changed after each measurement cycle, each measurement cycle including in each case the emission of an ultrasonic pulse 28 with the ultrasonic sensor 16.

In a variant of the method of the first embodiment, step S120 may be omitted and the detection of the first ultrasound echo 30 having the first amplitude 32 in the ultrasound signal of the first reception channel in step S130 is also performed in the ultrasound sensor 16 based on the received ultrasound signal of the first reception channel. The same applies to the subsequent detection of the second ultrasound echo 34 with the second amplitude 36 in the received ultrasound signal of the second reception channel in step S140. In this modification of the first exemplary embodiment, the first ultrasonic echo 30 and the second ultrasonic echo 34 having the first amplitude 32 and the second amplitude 26 are detected in the ultrasonic sensor 16 in separate steps and transmitted therefrom to the controller 14. Therefore, in step S140, only the cross-talk check of the first ultrasound echo 30 occurs in the controller 14. Thus, in this variant of the method of the first embodiment, step S140 does not comprise transmitting the second ultrasonic signal and does not comprise detecting the second ultrasonic echo 34 corresponding to the first ultrasonic echo 30 in the ultrasonic signal of the second receiving channel. Only cross-talk checking based on a comparison of the first ultrasound echo 30 and the second ultrasound echo 34 received by the ultrasound sensor 16 is performed in the controller 14.

When the ultrasonic sensor 16 has set its first receiving channel to the lower frequency f2 at which the second ultrasonic sensor 16, S2 transmits ultrasonic pulses, and has set its second receiving channel to the center frequency f1 at which the first ultrasonic sensor 16, S1 transmits ultrasonic pulses, the method may be performed in the same manner as the sensor located above the second ultrasonic sensor 16, S2 in fig. 1. A corresponding definition of the ultrasonic sensor 16 is obtained.

Alternatively, the method for identifying the object 24 described above with reference to the ultrasonic identification system 12 of the first exemplary embodiment may be performed entirely using one ultrasonic sensor 16. For this purpose, the corresponding steps of the above-described method are performed in the ultrasonic sensor 16, the ultrasonic sensor 16 having a first and a second receiving channel for ultrasonic signals as described above. In step 150, in case of a negative result of the cross-talk check, the ultrasonic sensor 16 outputs an identification of the object 24 for the detected first ultrasonic echo 30 to the controller 14.

List of reference numerals

10 vehicle

12 ultrasonic recognition system

14 controller

16 ultrasonic sensor

18 front part

20 rear part

22 data link

24 objects

26 ambient environment

28 ultrasonic pulses

30 first ultrasonic echo, first receiving channel

32 first amplitude

34 second ultrasound echo, second receiving channel

36 second amplitude

38 reception interval

40 ghost objects

Alpha beam angle

f1 center frequency

f2 lower frequency

f3 frequency.

Claims (14)

1. A method of identifying an object (24), in particular an object in the surroundings (26) of a vehicle (10), using an ultrasonic sensor (16), the ultrasonic sensor (16) having at least a first and a second receiving channel for ultrasonic signals, wherein the identification of the object (24) is performed on the first receiving channel for receiving ultrasonic echoes (30, 34), the method comprising the steps of:

receiving ultrasonic signals on the first and second receiving channels in accordance with at least one transmitted ultrasonic pulse (28),

detecting a first ultrasound echo (30) having a first amplitude (32) in the ultrasound signal on the first receive path,

checking the first ultrasound echo (30) for crosstalk based on the reception of the ultrasound signal on the second reception channel, and

in case of a negative result of the crosstalk check, an identification of the object (24) for the detected first ultrasound echo (30) is output.

2. The method of claim 1, wherein the step of determining the position of the substrate comprises,

checking the first ultrasound echo (30) for crosstalk based on the reception of the ultrasound signal on the second reception channel comprises: -detecting a second ultrasound echo (34) corresponding to the detected first ultrasound echo (30) and having a second amplitude (36) in the ultrasound signal of the second receiving channel, and-comparing the first amplitude (32) and the second amplitude (36), wherein the first ultrasound echo (30) is identified as cross-talk if the first amplitude (32) is smaller than the second amplitude (36).

3. The method of claim 2, wherein the step of determining the position of the substrate comprises,

detecting a second ultrasonic echo (34) corresponding to the detected first ultrasonic echo (30) and having a second amplitude (36) in the ultrasonic signal of the second receiving channel comprises: -detecting the reception of the second ultrasound echo (34) within a reception interval (38) starting from the reception of the first ultrasound echo (30).

4. A method according to claim 2 or 3, characterized in that,

identifying the first ultrasound echo (30) as cross-talk if the first amplitude (32) is less than the second amplitude (36) comprises: the first ultrasound echo (30) is identified as cross-talk if the first amplitude (32) is less than the second amplitude (36) by about one channel spacing or more between the first receive channel and the second receive channel.

5. The method according to any one of claim 2 to 4, wherein,

the ultrasonic sensor (61) for identifying the object (24) is designed to receive ultrasonic echoes (30, 34) on the second receiving channel and

the method comprises the step of checking a second ultrasound echo (34) for cross talk based on the reception of an ultrasound signal at a first reception channel, wherein checking the second ultrasound echo (34) for cross talk comprises detecting a first ultrasound echo (30), which first ultrasound echo (30) corresponds to the detected second ultrasound echo (34) and has a second amplitude (36) in the ultrasound signal of the first reception channel, and comparing the second amplitude (36) with the first amplitude (32), wherein the second ultrasound echo (34) is identified as cross talk if the second amplitude (36) is smaller than the first amplitude (32).

6. The method according to any of the preceding claims, characterized in that,

the method comprises the step of providing a first receiving channel and a second receiving channel.

7. An ultrasonic sensor (16) for identifying an object (24), in particular an object (24) in the surroundings (26) of a vehicle (10), having at least a first and a second receiving channel for ultrasonic signals, wherein the identification of the object (24) is performed on the first receiving channel for receiving ultrasonic echoes (30, 34), wherein the ultrasonic sensor (16) is designed to perform the method for identifying an object (24) according to any one of claims 1 to 6.

8. The ultrasonic sensor (16) according to claim 7, characterized in that,

the first and second reception channels for ultrasonic signals are distinguished by frequency shifting and/or by modulation, for example as chirped up or chirped down.

9. An ultrasound recognition system (12) for recognizing objects (24), in particular objects in the surroundings (26) of a vehicle (10), using a plurality of ultrasound sensors (16) and a controller (14), the plurality of ultrasound sensors (16) having at least a first and a second reception channel for ultrasound signals, the plurality of ultrasound sensors and the controller (14) being connected to one another via a data link (22), wherein for at least one of the ultrasound sensors (16) the recognition of an object (24) is performed on the first reception channel for receiving ultrasound echoes (30, 34), characterized in that the ultrasound recognition system (12) is designed to use the at least one ultrasound sensor (16) to perform the method for recognizing an object (24) according to any one of claims 1 to 6.

10. The ultrasound identification system (12) of claim 9, wherein,

The ultrasound recognition system (12) is designed to transmit the ultrasound signals received with the at least one ultrasound sensor (12) on the first receiving channel to the controller (14), wherein the controller (14) is designed to detect a first ultrasound echo (30) having a first amplitude (32) in the ultrasound signals of the first receiving channel, and/or

The ultrasound recognition system (12) is designed to transmit the ultrasound signal received on the second receiving channel using the at least one ultrasound sensor (16) to the controller (14), wherein in particular the controller (14) is designed to detect a second ultrasound echo (34), which second ultrasound echo (34) corresponds to the detected first ultrasound echo (30) and has a second amplitude (36) in the ultrasound signal of the second receiving channel.

11. The ultrasound identification system (12) of claim 9, wherein,

the at least one ultrasonic sensor (16) is designed to detect a first ultrasonic echo (30) having a first amplitude (32) in the ultrasonic signal of the first receiving channel and to transmit the detected first ultrasonic echo (30) to the controller (14), wherein the at least one ultrasonic sensor (16) is preferably also designed to detect a second ultrasonic echo (34) corresponding to the detected first ultrasonic echo (30) and having a second amplitude (36) in the ultrasonic signal of the second receiving channel and to transmit the detected second ultrasonic echo (34) to the controller (14), wherein

The controller (14) is designed to check the first ultrasound echo (30) for crosstalk based on the reception of the ultrasound signal on the second reception channel.

12. The ultrasound identification system (12) according to one of the claims 9 to 11, characterized in that,

the ultrasound recognition system (12) is designed to emit ultrasound pulses (28) using a first ultrasound sensor (16, S1) on a first transmission channel, which preferably corresponds to a first reception channel, and to execute a method for recognizing an object (24) using adjacent ultrasound sensors (16).

13. The ultrasound identification system (12) of claim 12, wherein,

the ultrasound recognition system (12) is designed to emit ultrasound pulses (28) substantially simultaneously on a second transmission channel using a second ultrasound sensor (16, S2), wherein the second ultrasound sensor (16, S2) is arranged adjacent to or preferably at a distance from the ultrasound sensor (16) performing the method for recognizing an object (24), wherein particularly preferably the second transmission channel corresponds to the second reception channel.

14. The ultrasound identification system (12) according to one of the claims 12 to 13, wherein,

The ultrasound recognition system (12) is designed to modify the configuration of the ultrasound sensor (16) to the first ultrasound sensor (16, S1) and/or the second ultrasound sensor (16, S2) and/or to execute the ultrasound sensor (16) of the method for recognizing the object (24) during operation, in particular after each measurement cycle of transmitting ultrasound pulses (28) with the first ultrasound sensor (16, S1) and/or the second ultrasound sensor (16, S2).